I'm not sure how prevalent piracy was in ancient Greece, but if it was I'm sure it was bad ***. Like Samuel L. Jackson bad ***. I think this build recreates with fair accuracy how sick Greek Pirates were.

Where I'm coming from with regards to this build:
I was playing a game a while back against a team that was really terrible. But there was this one Pantheon on the team that was actually putting up respectable numbers. He was relatively difficult to kill, and yet was putting out a fair amount of damage. Confused, I checked what he was building and noticed the conspicuous use of Bilgewater Cutlass. As the game progressed, he kind of flubbed the build, rushing the Hextech Revolver and a Phantom Dancer, and became gradually less of a threat. Nonetheless, the seed was planted: I knew there had to be something to this Bilgewater business. I hashed and rehashed this build in various forms, some tanky (picking up Randuin's, etc.), some with their balls to the wall full of B. F. Swords, usually ending my build out selling the cutlass for something else late-game. But I wasn't really satisfied with any of these builds.
Then I saw that Chaos Dunk video on Youtube, and realized that maybe AP shouldn't necessarily be verboten on Pantheon. That's when I looked at his AP ratios, and liked what I saw. So that's when I decided that maybe the Revolver isn't such a bad idea after all, and Trinity Force is one of my favorite items, so let's mash them together with the B. F. Sword madness and see what happens.
But then my hard drive fried and I couldn't play for two weeks, but when I came back I whipped this build out and went 13/5/22 (because Kassadin and Tryndamere kept stealing my kills).

Now, before you throw up your arms in outrage at some mild unorthodoxy, let me explain a couple of things:

Pantheon is one of the squishiest champs in the game, and can have some difficulty as the game matures and you pass from level 6-13-ish (i.e. before your AD has really stacked up, but after your monstrous early game presence wears off). The trouble is, early on, it's pretty tough to find HP items that really get you going in the AD arena as well. Luckily, lifesteal is nearly just as adequate as HP at keeping you alive (especially in the small skirmishes of early/mid game). Bilgewater Cutlass ends up being the perfect item, providing you with a fair amount of damage and a healthy dose of lifesteal.

Some of you may cringe at the 100 or so AP floating around this build, feeling that it's unwise to invest any gold anywhere besides AD (or defense). Let me defend my position in two ways. 1.) Both Aegis of Zeonia and Grand Skyfall get 100% of your AP in bonus damage, so that little bit of AP goes a long way--your Aegis will be dealing just under 300, plus you'll get 300 free from Hextech Revolver, AND you'll proc Trinity Force getting even more bonus damage! 2.) I will post an AD-purist variant of this build in the "Items" section for all the haters.

Exhaust
I don't think anyone should really see any problems here. Exhaust is an awesome spell for the melee-DPS man. It might seem to make Bilgewater Cutlass redundant, but trust me, all those times you said, "Damn, I wish Exhaust lasted just a little longer," should make you take comfort in your badass cutlass.

Flash
If you build your masteries far enough down the Utility Tree, you'll achieve a healthy mana supply with which to cast, meaning that you won't need to rely on Clarity to use your skills. And thank god, too, because Flash is a fantastic spell for Pantheon. There are many things that the spell provides: Getting in range for one final spear toss, instant ganks from out of the bushes, etc. But most importantly it gets you to safety fast. You don't have the durability to try and break through their ranks and escape with Ghost, rather you need to get out of harm's way instantaneously. And that's exactly what Flash does. When you block with Aegis Protection and Flash to safety at the brink of death, they're going to get mad at you.

If you're disgruntled about my spell choice, don't worry, Pantheon has the added advantage of making impressive use of almost all the summoner spells:

TOP PICKS
- I feel that this is a must-have if you don't spec far down the Utility Tree because Pantheon is just too mana-starved to succeed without it. Manamune is a viable alternative, but its cost in time and gold, just makes Clarity seem more efficient. Further, this spell is great for fooling opponents into thinking you're OOM and useless, only to refresh your pool, stun them, and crush them. You'll also be glad you have it after you use Skyfall, which often bankrupts your mana.
- Great skill for all champs, especially melee ones that make heavy use of both pursuit and flight.
- This, combined with Skyfall, means that you own the map. You do whatever you want, wherever you want. Great spell.
- This can be incredibly useful for correctly placing your Skyfall, as well as just being a very useful spell to have.

FOOD FOR THOUGHT
- This can free you up to get some other boots besides Merc Treads, as well as getting you out of tight spots. I still don't think it's as potent as other spells on this champion, though.
- Extra DPS never hurt anybody because sometimes that last spear throw just isn't enough. However, with the double slow from the Cutlass and Exhaust, last-hitting is fairly easy without this spell.
- Helpful skill to add some survivability, but I think Flash does this just as well, while providing other utilities that Heal does not. I find I usually get by fine without it, meaning that you should probably prioritize other spells over this one.
- This way you don't have to feel so bad about abandoning your tower to Skyfall and pick up some kills. But Teleport can provide similar security, while providing other extremely useful services that Fortify cannot.
- Because Skyfall allows you to be anywhere on the map, you can actually pull off some cool stuff. For example, you can recklessly initiate (dealing swaths of damage), die, and then immediately Skyfall back into the fray (with 400 extra HP) to pick up some serious kills/assists. But don't get too excited, even speccing into it, you still only get to pull this gimmick every 8 and a half minutes. Moreover, when you use this spell, you're still dying, which is the opposite of what we want. Good spell if you're toodling around, but there are far better ones for when you're actually playing.

Runes

Marks

Greater Mark of Desolation - I can't really think of any scenario where I'd recommend any other Marks besides these. I suppose Alacrity Marks could be kind of cool for proccing Aegis Protection much more often, but I think in the long run, this wouldn't be as beneficial as the ArPen

Seals

Greater Seal of Evasion - I just like Dodge Runes. These, combined with your passive can make you uncannily difficult to kill.
Greater Seal of Scaling Mana Regeneration - These are another good choice, especially if you decided against Clarity. I take these over Flat Mana-Regen Seals any day because you'll be mana-hungry all game.
Greater Seal of Vitality - These will help make you less squishy. I think Flat HP Seals are equally as viable.

Glyphs

Greater Glyph of Scaling Ability Power - You might not be too happy with me on this one, but the way I see it, this is a free extra 30 damage from your Skyfall and Stun by level 18.
Greater Glyph of Scaling Magic Resist - These are never a bad idea, and in fact, I'm not entirely sold on the idea of choosing AP Glyphs over these. I'd never take flat MagRes runes because magic damage usually isn't too scary until late-game.
Greater Glyph of Scaling Cooldown Reduction - These will allow you to use your Skyfall much more often. I prefer these over flat CDR Glyphs because your cooldowns are perfectly acceptable until you get Skyfall at level 6, at which point these begin to provide you with more reduction.

Quintessences

Greater Quintessence of Health - I've always really liked these as they let you play with a little more gusto early on.
Greater Quintessence of Desolation - More ArPen never hurt anyone
Greater Quintessence of Magic Penetration - I think this would be the best place to boost your magic damage a little.

Masteries

What I'm running right now is what you see above, 19/0/11, as suggested by ZeroRacer (thanks, brah).

Basically, the goal here is to get enough mana regen to forgo Clarity, and surprisingly the little bit provided by Meditation is all you really need to achieve that mark. Sure, you can't spam quite as hard early-game, but you can spam enough to harass out even the most stalwart of them.

About Havoc

Havoc sucks. Even with the recent changes, it still sucks. Let's say I deal 1000 damage in one hit, Havoc only gets me 40 bonus damage. And, sorry, you'll never be dealing that much in one hit. 500 damage per hit? Hooray! Havoc has given me 20 extra damage. Dumb. You might possibly see some benefit out of this during the first couple levels of play, but I'm not too big on using something that's useful until level 3, and then becomes basically useless for the next 16 levels of play.

Further Explanations

Alacrity - To be entirely honest, these 4 points are basically useless, and serve merely to make available the 10% extra crit damage from Lethality. I put them in Alacrity simply because it will help slightly in proccing Aegis Protection and minion last-hitting. Also, early-game it might be just enough to get that one extra last hit you needed for First Blood.

Archmage's Savvy will provide you 10 free damage on your stun and Skyfall, but only by Level 18. I now realize that, at that stage of the game, this extra damage is totally negligible. True, at the full build this would boost you to a 70 damage bonus to your stun/Skyfall. But I mean really: 60 damage, 70 damage, it's all the same in the dark.

Brute Force is even more useless. I really hope that the developers do something to make this not a total waste. 3 AD. Might as well be 0 AD.

I chose Expanded Mind because I usually get along fine without the extra experience, and the increased mana pool goes so far for me as to make it worth the investment.

While I think Lethality is worth the investment (since we auto-crit thanks to Heartseeker Strike's passive), you might not. In which case, there are other avenues you can take:

On A New Alternative

12/0/18
This will provide you with some very cool stuff.
1.) Increased Buff duration from Utility Mastery is always helpful.
2.) Quickness can provide you the edge you need to get off a stun or last hit with your spear.
3.) Blink of an Eye makes Flash incredibly more useful
Meanwhile, you'll still get your MagPen and ArPen in the Offense Tree, which is all that really matters there.

Now that I'm thinking about it, I might start speccing this way (I should play with it first, though before I make any claims).

Of course, my old standard 21/0/9 build works just fine (with Clarity of course), and sometimes I still run with that. Don't forget to drop your 9th Utility point into Insight, if you've got the right team for it.

Tangentially

If I decide to Off-Tank (which is another build entirely), I'll take a 12/18/0 approach, getting ArPen and MagPen in the Offense Tree and all the obvious stuff in the Defense Tree.

Hypothetical Queries

Why do you like spending points on Magic Penetration?
For your Stun and Skyfall, silly! Plus it helps you out if you take things like Ignite or Sunfire Aegis. Moreover Sorcery is good for this CDR-light item build.

Why do you have such a ******* for the Utility Tree?
Sure, for many physical carries, The Defense Tree makes the most sense as your secondary tree because you have to spend a lot of time standing around using your auto-attack. As such, Defense helps you auto-attack for longer and your mana situation is practically irrelevant.

However, an important thing to realize with Pantheon is that he is, at heart, a caster. Most of his DPS derives from using his abilities. These abilities simply draw upon his AD rather than his AP (With the obvious counter-examples excluded). Being that the Utility Tree is the preferred avenue for casters, it just makes sense that Pantheon would want to take advantage of it.

The idea is basically that we get a bunch of mana management in the Utility Tree rather than a little more survivability in the Defense Tree, and I really do feel that this goes very far for your DPS output.

The guy that won't shut up about "mana management", picked Good Hands?
Yes I did. There's various literature (which I'm somewhat ashamed to say I've read) about this highly fascinating and enlightening debate. The summary is that the HP and Mana Regen provided by Perseverance is totally impotent and useless by the end of the game--in fact you probably won't even notice you specced into this by the end of the match. Good Hands, by contrast can be incredibly clutch towards the end of the game. Reviving nearly 10 seconds earlier than everyone else is great for any champ, but remember: you're a guy that can teleport anywhere on the map. These extra seconds can be beyond invaluable for a win.

Pantheon's skills are very easy to use.

Aegis Protection (Passive) - I love this ****. Just attack the minions 4 times and harass with no consequence. This actually makes you frightening in the middle lane, especially against somebody like AD Ezreal. Plus it makes quick tower-dives totally and completely safe. (as long as nobody is MIA)

Spear Shot - Big time damage here. I just spam this all the time. Be a **** and harass like crazy. Once you burn through your mana, Clarity up and slow it down for a bit.

Aegis of Zeonia - Great stun. One of my favorite gank-initiators in the game. Be careful when using it defensively because you'll throw yourself back into the midst of your opponents--pay attention to who has more and less movement speed than you.

Heartseeker Strike - Impressive damage, but watch out for weird terrain that can make this uncastable and ruin the crucial timing that this needs to be really effective.

Grand Skyfall - This is a really fun skill. Anyone that's backdooring is basically already dead if this is off cooldown. Remember that landing directly on top of someone is nice, but it's often better to err towards their escape route rather than towards your tower. Also, you can Skyfall into the jungle or the river just to be really sneaky. Also, a common mistake I see is Skyfalling into a group of three enemies and then complaining in all caps, "WHERE THA **** WERE YOU GUYS!?" You can't 3 v 1 people, don't even try. And if you're doing something ballsy, ping first so people know what's happening.

Don't put too much stock in my skill sequence. Pantheon is very flexible, and I feel that both Spear Shot and Heartseeker deal equitable damage given their most favorable circumstances. Basically, while you're harassing beef up Spear Shot. When you're fighting champs (or pushing) in earnest, put points in Heartseeker. It's always good to have a point in Heartseeker early on because it makes last-hitting minions really easy.

While I still feel the above statement is true, here's an alternative method of determining how to look at the decision: Spear Shot's AD ratios are absurd, and only get more absurd as you level it. So, once you start to get more serious AD (maybe after your first B. F. Sword) make this your priority. It's cost and cool down are way lower than Heartseeker Strike, so when you've got the AD to back it up, Spear Shot will probably give you lots more damage. Keep in mind, however, that that damage is single target where Heartseeker's will hit multiple opponents.

There are really only two distinguishing characteristics of this build as compared to other more standard Pantheon item line-ups. They are

So, the big question is why bother with this item? It costs 1825 gold, which is almost 200g more than my first B. F. Sword, so why wouldn't I get that instead? Well, let's back up a second. First of all, unlike a B. F. Sword, the Cutlass builds in stages meaning that you don't have to wait until you have mounds of gold stockpiled to get any noticeable uprgade in your stats. I find it's pretty convenient to be able to recall after some initial skirmishes with 1325g and pick up Boots and a Pickaxe. This maintains your presence in the lane, unlike a situation where you were saving up for a single big-ticket item which would have said presence wane over time.
Furthermore, we have to look at some other elements. Certainly, damage is your most important stat, and there's no denying that a B. F. Sword will give you double the AD boost that the Cutlass does. But with the Cutlass, you get more: 12% Lifesteal (15% with your Doran's Blade) which sustains you for a maddeningly long time. Further, it builds into Hextech Gunblade, which will provide insane SpellVamp healing late-game. Secondly, a lot of your gold is being invested in the active ability of The Cutlass: "Deals 150 magic damage and slows the target champion by 50% for 3 seconds (300 range). 60 second cooldown." You're now a much scarier chaser/finisher, and you get a free 150 damage every minute.


With that said, it's important not to get too excited and rush your Hextech Gunblade immediately. B. F. Swords, I think, are still probably your best item choice (once you have some early-game strength to get that bread). Every time I play this champ, it's when the B. F. Swords start stacking that I notice my damage start to really spike.

But don't discount the Gunblade altogether. 60 AD is damn good--that's more than a Black Cleaver, and as much as a Bloodthirster with no stacks. It gives a good amount of AP, which is nice for your other two abilities. With a better understanding of Lifesteal and Spell Vamp, I like this item even more. 20% Lifesteal will go a long way for your auto-attack, while 1v1-ing and waiting for your abilities to come off of cooldown. The 25% Spell Vamp will be huge at all times, as every single one of your skills will refund 25% of the damage dealt back to you as HP. Hitting a whole team with Heartseeker Strike will mean immense healing! (though likely will not be enough to protect you from 5 ultimates, i.e. don't play like a *****).

Yeah, the Hextech Buff was totally sick.


This is another really expensive item, but one I think on the whole, absolutely worth the price. Boosted Movement Speed makes you even more threatening as a chaser, but also allows you to initiate ganks even more effectively.

Then it gives you a little bit of everything: AD, AP, HP, Mana, AS, Crit; all stats you make use of.

It also gives you a possible slow, meaning that in a single fight you could potentially throw out a gnarly trifecta of slows.

Finally, your abilities will proc a 150% base-damage boost. This means your next attack will do something like 150 bonus damage. With Spear Shot on a low CD, you can proc this pretty much every 3 seconds that the perk is off cooldown. To compare it to Bloodthirster (assuming Pantheon does not attack much more than once every second), I think you'll need something like 20 stacks to match this damage bonus (and you'll lose those every time you die--although you're pretty hard to kill while playing this build). I'll take a small and debatable damage reduction to get all the other various bonuses this item has to offer.

Youmuu's Ghostblade - This would probably be my number one substitute (still waiting on enough games that make it this far, so that I can have enough empirical experience to compare the two). Its active is great: It allows us in some form to keep the movement speed bonus that I like so much from Trinity Force as well as the AS (which can make stuff like Lizard Buff go a long way). Cooldown reduction is a pretty big deal as well. But perhaps most importantly, it helps us in dealing with Armor.

Sunfire Aegis - This is a really great item to use to get some extra survivability, especially against heavy physical-damage based teams. But as an added bonus, since your purchase of this means that you're having a difficult time getting your K/D/A values where you want them, and therefore the steady income you need, it helps immensely in your farming efforts. With the AoE Dot, you'll be able to take out an entire creep wave by the time Heartseeker Strike finishes casting. This has become my number one defensive replacement item.

Frozen Mallet - This could be another really great substitute, especially if you find your K/D slipping as you head into late-game. It gives almost as much AD as the items I'm currently discussing, but also a whopping 700 HP. Moreover, with this you'll be guaranteed 3 slows on top of your stun. You'll be a black hole; 1v1 nobody will be able to escape. As a bonus, if you need even more survivability, this would give you enough HP to potentially justify selling one of your B. F. Sword items to purchase Atma's Impaler (you'd get about 60 AD from the passive)--but the wording is such that I don't know if Atma's damage would be factored into your skill's ratios. If it's not, then forget it.

Phantom Dancer - I just don't like this item on Pantheon. No AD means your skills will see no benefit from it, and we rely on those most of all for our DPS. Sure we get to keep a nice movement speed, but it still won't give us enough crit chance for our crits to be a reliable source of damage. The AS is nice, but it's an empty promise. We have to achieve a balance between our auto-attack and our skills with this champ, and Phantom Dancer fails us in that regard.

Really I guess this comes down to personal preference, so that's why I post in the next section a more straightforward AD Build, feel free to synthesize that one with my main build.

Core Build

Most games this is what you'll be looking at:

As Regards the Remainder

Starting Item

- Doran's Blade
After much deliberation, I finally decided that this is my favorite item to start off with when playing as Pantheon. The HP makes you less squishy and it gives you plenty of AD. 3% Lifesteal doesn't seem like all that much, but trust me, it's enough to give you staying power until you reach level 6.

Plus, we're not rushing any items that build out of a Long Sword so it's not as crucial to start with that.

Filling it Out

- Infinity Edge
This item doesn't get too much love in Pantheon builds, but I think that the combination of 250% crit damage with Heartseeker Strike's passive effect make this a serious threat to opponents. Late game, when cocky tanks think their HP is thick enough to waltz around while they're at 15% health will get reprimanded handily. Now that this item provides a whopping 80 AD, don't hesitate to buy it.

- The Black Cleaver
Maybe not the best item for a champ that doesn't rely so much on auto-attack, and a build that doesn't focus on AS so much. But this is your only armor-counter, and I think that makes it important (I don't think Last Whisper is going to give you enough AD to make the cut). Plus between this and Trinity Force, you'll have at least decent AS to make use of the debuff.

The bottom line is, however, that either or both of these could be readily replaced by Bloodthirster

- Banshee's Veil
I automatically assume that by the end of the game you'll be getting mauled by CC and Nukers. But if you managed to avoid such a scenario, here are the best alternatives:

Last Whisper - This is a quick and easy way to deal with armored tanks. But if you already bought Black Cleaver, forget about it as they don't play together. With the recent mild nerfs to B. F. Swords, the damage disparity between one of those and Last Whisper is now only 5 AD, couple that with the item's massive ArPen and you'll be getting a much more noticeable damage boost. What this means is that if you have the enemy team on the ropes Mid-Game, go for this instead of a second B. F. Sword, but if it looks like you're in for a long game (and there isn't an ungodly amount of armor stacking up), hold out for The Black Cleaver.

Guardian Angel - Yeah, another defensive item. But this does something very different from Banshee's, which is extremely useful to a squishy carry that's getting focused, such as yourself.

Wriggle's Lantern - More Lifesteal, More AD, some armor. Plus you get another useful active ability, making you a bad *** utilitarian.

Boots

Besides Mercury's Treads or Ninja Tabi I always like to pick up Boots of Swiftness to make chasing even easier.

Other Items to Consider

Guinsoo's Rageblade - This would fit in with our motif of hybridizing Pantheon, and it works well with spammable skills like Spear Shot. I'll admit that I've never tried this, but I think it could work.

Quicksilver Sash - This item is so cool. I haven't decided whether or not I like it better than Banshee's Veil.

This build still works on the same premise of the improved early/mid-game provided by Bilgewater Cutlass, and as such Your core build and item priority should remain the same (Cutlass, Boots, 2 Swords).


When your focus is AD, I don't think you need to rely as much on sneaky bonus damage, like you would in my main build, so we just go all out with our Bloodthirsters. The lifesteal of this build is ridiculous.

Spell Rotation

--> --> -->

A lot of times you won't have the advantage of using that opening Spear Shot, but you should always try to do so to max your DPS. Of course, if you're ganking from within a bush, don't blow your cover with Spear Shot and then try to stun (the exception being if they've REALLY over-extended).

Don't think just because you stunned an opponent you can take on a 2v1. You can't, the stun doesn't last that long and it'll leave you very exposed. Plus in situations like that you might stun, but it's highly likely that the opponents will hit you with CC of their own, meaning that you won't be able to capitalize on their momentary disability.

Aegis of Zeonia works best in 1v1 scenarios and in conjunction with your teammates. Always keep that in mind when casting it.

Early Game

In the Side Lanes

Why take Spear Shot instead of Aegis of Zeonia; isn't it almost LoL doctrine to pick up your CC spell immediately to grab First Blood? Sure, having a stun at level 1 can make a big difference in nabbing a kill right off the bat. But the way I see it, because your Stun requires that you over-extend yourself, your opponents will have to be pretty terrible to allow you to stun, get a kill, and get away scot-free. I really think you'll get a lot more mileage out of the superb harassing power of Spear Shot, so that when you make it to level 2, your opponents will be nice and soft for you to execute with a Stun and Exhaust. Try to cast a Spear Shot before you stun, so that it'll be off of CD in time to act as a finisher.

Harass like crazy until the two of you gain the dominant lane control. When this happens you and your partner should have more freedom to set up good positioning, at which point you can Stun and the two of you can nab a kill or two.

If they have hard pushers like Mordekaiser that prevent you from wresting lane dominance, back off to your tower. It's okay if your HP gets somewhat low when you're turtling because you have awesome tower-trap capability. When they get in too close, or pull tower aggro, stun and let loose your combo.

Soloing Mid

Some of my most fun games as Pantheon have been when I've taken the middle lane. Don't hesitate to volunteer for this position if nobody on your team is stepping up. Here's why:

Although you are a "melee" champ, you can go toe-to-toe with most ranged opponents for two reasons. The first is that Spear Shot has good range, is on a low cool-down, has a low cost, and deals significant damage meaning that you can work away opposing HP without trying to get into melee range. Spear Shot is also an effective means to last hit minions if somebody like Tristana is pushing you away from the wave. Secondly, Aegis Protection does wonders for you against ranged physical carries. You can neglect almost all of the incoming damage by proccing this skill as often as possible. But watch out for casters because they DGAF about this ability.

One more thing to say is that picking up Spear Shot early on is even more important because you won't have enough DPS at level 1 to make very much use of your stun and pick up a kill. Rather, your opponent will probably be harassing you to *****ville and back, so you'll desperately need to respond in kind, and that's what Spear Shot is for.
Taking the middle lane, I feel also makes Clarity even more important, as spamming Spear Shot is even more crucial here than in the sides.

Take it easy, farm, work their HP down until they burn through their Health Potions. Then you can bring it down on them hard when they get too relaxed.

If you get cooked, back off and let Doran's Blade heal you. With 3% Lifesteal this may seem to take a while, but just be patient. Your Spear Shot can usually keep your opponent away while you heal. And at level 6, you can recall with no consequence thanks to Grand Skyfall

Mid Game

For the purposes of this guide, I'll define mid game as from the time after you begin ganking until significant team-fights break out. Because of Skyfall, even if you took the middle lane, you can abandon your post to go on the hunt for a quick kill. Bushes are a Pantheon's best friend. Hide in them until opponents get within stun range (be sure to ping ahead of time, so your peers know what you're doing) and then stun, and cast Heartseeker Strike. Try to cast it in such a way that the enemy either has to run through its area of effect or into the waiting arms of your teammates.

You're also a good counter-jungle champ as you can surprise opponents struggling to get buffs with a Stun, forcing them to helplessly tank the monsters for you as wipe away their HP. As a bonus, Heartseeker Strike will damage the enemy AND the monsters, making it super easy for you to get a kill and walk out with some buffs. If you see enemy champs MIA, check the jungle--but again, use the bushes because if they're tag-teaming Golem or some such and you charge in, you'll be in a bad way.

While you're ganking keep an eye on the minimap to be aware of the lane you just abandoned. If the gank is taking to long, forget about it. The good news is, with your ultimate, you have time (in fact it's even better) for lane opponents to make it all the way to the tower. That way you can drop on top of them, and probably get a neat kill out of it. In effect, on a good day, Pantheon ganks are twofers.

Late Game, Or Team Fights

The only thing you really need to keep in mind is that you can never initiate. If you do, you'll die, and I hope your team berates you.

Be wise about your use of your stun. You don't necessarily need to open with it, because unlike in 1v1 scenarios, unstunned champs are more likely be within and remain within the AoE of Heartseeker Strike in big fights (just by the nature of the beast). Having your stun available can come in handy when gnarly ultimates like that of Miss Fortune are cast. You can be a hero and shut them down immediately. Other good targets are healers like Soraka and Taric.
Your stun can also be used to trap opponents in your team's own gnarly ultimates, like say that of Nunu & Willump. This same logic can apply to your Hextech Gunblade, although it may be better to save it for the aftermath when your team is cleaning up stragglers.

Using the Gunblade

Just like Exhaust can be invaluable in both offensive and defensive situations, so too the Gunblade. Offensively, you can either use it initially to ensure that you'll make into stun range (this works best if you know your Skill Combo is enough to burn them down), but many times it's best to save it for when they try to flee.

Defensively, take advantage of its huge range. You can escape a lot of ganks by blasting the right enemy with this active ability. Generally, it's wisest to hit their main CC'r, but pay attention to who has the Phantom Dancers or Boots of Swiftness or Force of Nature, etc. I've escaped even Blood Scent Warwick with regularity by nailing him with the Gunblade.

Thanks for making it all the way through this guide. I hope it helped somewhat, or at least got you thinking about Pantheon in a less dogmatic way.

At the end of the day, my goal is just really to remind about the merits of Bilgewater Cutlass, so go out there and show off your Pantheon's newfound saltiness and scruff. I mean, what's cooler than an Ancient Greek Pirate? Samuel L. Jackson being an Ancient Greek Pirate, and instead of using boats, he rides great white sharks, and drinks brandy with James Bonde while pillaging the feeble and corrupt and being in the cut with the finest of wenches?

Yes.

Because this build is far from perfect, criticism is as greatly appreciated as praise, so please leave constructive feedback to help me improve!

3/9/2011 - Fixed some erroneous information about Lifesteal, SpellVamp, and Crits (thanks to Jebus McAzn). Decided ultimately to keep Trinity Force, though I added in some alternatives. I still would very much appreciate suggestions as to possible replacements.

4/12/2011 - Found a couple more bits of erroneous information and edited those. Also, updated the guide to reflect the most recent patch changes. Finally, play-tested Sunfire Aegis with success and have made that a recommended replacement item.

5/8/2011 - Changed my masteries on the suggestion of ZeroRacer, and as a result also changed my preferred summoner spells. More detailed updates to follow soon. Also dropped Zeal out of my item list, as I very rarely now start to build Trinity Force before I finish Infinity Edge. And in the event that I do, I'm more inclined to build Sheen first anyway. Third, I changed my skill sequence to reflect the one I've been using for a while know, which maxes Spear Shot much faster. Finally, swapped the order of Trinity Force and Banshee's Veil, as BV is a vital necessity where TF is self-indulgent.

6/11/2011 - Finally got around to those updates I promised. As a result, My "Summoner Spells" section has been moved around and edited. As well, my "Runes and Masteries" has grown more verbose.