It all started when I saw just how much Pantheon was getting nerfed. But that's when it came to me. Only his attack damage scaling abilities were getting nerfed. So I decided on trying a build that utilized AP. Surprisingly, it worked well. This is just sharing what you may do if you ever find yourself craving some competitive pantheon.

Why should you try this?
His ultimate is his teleporting spell, and it helps slow his enemies to stun them. However, did you know that it has a ONE to ONE ratio to AP? Well, that's 1000 + Your AP amount here! Don't worry, even if they're out of the circle, you still have the chance to do 33% of that damage if they're BARELY out of it! Don't forget, with Hextech Gunblade, you will lifesteal 7% of ALL the damage that you do inside this circle! You don't even have to initiate with this; if you're low health and they're all running away, then you can ult in front of them while they try to start a fight with you, and watch their terrified faces as you regain your health instantly after your teleport!

Don't worry, the rest will be explained in this passage!

Pros:
Amazing AOE nuke capability
1:1 AP Ratios
GREAT passive that can block crowd control effects
You can crit at 15% of your enemy's health
Stun with 15% cooldown is only 5.5 seconds long
Great spell-vamp that really comes in handy
EXTREMELY expensive builds, MUST farm LOTS of minions!!!
Cons
Very squishy
Prone to CC
Takes skill to aim ult correctly
Has no real way to escape properly
Less AD power with hybrid; almost the same

Magic penetration marks are decent on hybrid Pantheon, but if you decide to use Greater Mark of DesolationArmor penetration, go for it! It's your choice between HIGH burst damage and sustained damage; Since Pantheon IS a melee champion, Armor Penetration is definitely better early game; however, late game the extra magic penetration gives him higher burst potential and better magic damage against tanks.
Quintessences are varied. You can try Greater Quintessence of DesolationArmor penetration or Health quintessences. Personally, I like Health quintessences better; keeps you alive while you keep that pressure on your enemies while they're running away.

Pantheon is one of few great melee farmers. His passive blocks an attack every 4 auto-attacks or spell casts, and his Heartseeker passive makes killing those cannon minions a breeze. Don't forget his ranged Spear shot, which has a high AD ratio for last hitting and harassing. You generally want about 60-70% of the minion kills in your lane, and doing so will guarantee you a higher count of minion kills than most people. WARNING: It is VITAL that you get these minions early game, or else you WILL fall off late game. It's not just about killing champions; Champions are only about 20-30 minion kills worth; You MUST establish a minion farming strategy with every champion in order to succeed.

The reason why I level Aegis of Zeonia first is because the higher the level of the ability, the longer the stun. Which is why you might really hate Mercury's treads. Anyways, Spear shot's AD ratio increases each level you level it, but Heartseeker strike is a possible AOE nuke. I say that these two are equally important. Obviously, your ult takes priority over anything else.
Soon you will find a better way to synergize all of your abilities equally well to the benefit of your team.

Passive - Aegis Protection - Your favorite passive in the laning phase. Auto-attacks from champions will have nothing on you, allowing you to farm freely.

Spear shot - 135% of AD. Crazy ratio. Your main source of sustained damage after your initial ult + W burst. You can easily harass enemies in lane with this, as well. Procs Lich Bane for some massive beatdowns.

Aegis of Zeonia - 100% of AP. This is your key spell in Hybrid Pantheon; easy stun as well as a semi-short cooldown.

Heartseeker strike - 35% of AD. **** good if you can get them to stay in the area of your strike. Great for farming minions. Its passive is INCREDIBLE if you have Infinity Edge and Lich Bane proc; Every champion you face will die immediately at 15% health (except durable tanks [DAMN YOU RAMMUS]).

Grand Skyfall - An amazing teleport that can massively nuke almost any character. If you must... You can use this spell to defend towers... Although I REALLY hate using it to do that -.-.

- Great for getting those VITAL early game kills, you will laugh in their faces as they run away with 4 hp and ignite them. Don't forget tryndamere...

VERY VIABLE Summoner spells -

- Chasing, running away; it's extremely versatile.

- If you like an easy time to chase down enemies, pick this spell. If they have a tryndamere, pick this spell. It's decent; however its your choice if you pick this or Flash.

SEMI-VIABLE Summoner spells -

Ghost - Chasing and running away; just not as immediate.

Cleanse - Good for getting out of a CC fest.

Teleport - You already have your ult, but if you have a Teemo and feel like backdooring stealthily, go for it!

Heal - This is only really helpful in the laning phase; late game it really falls off as your opponents can likely do more than 300 damage to you and your allies easily.

Any other summoner spell - No.

Rally - 200 HP beacon, will get destroyed in seconds.
Revive - 9 minute cool-down and spawn-timer has gotten nerfed.
Clairvoyance - If you need to sacrifice a summoner spell for this, tell your support to do it.
Fortify - Teleport is a better defence than this, as well as allowing you to backdoor; you don't need the extra damage to minions either.
Clarity - Pantheon? Mana hungry? Get MANAMUNE!

Mejai's Soulstealer - You are an assassin, or at least you have the ability to be one. Your ult guarentees a teleport every 100 seconds. You WILL score a few kills, no doubt (unless you REALLY suck) or at least assists. You have a stun, and this ult also slows enemies while doing massive damage to them. Plus, if you get 20 stacks, you get a 15% CDR bonus.

Sword of the Occult - Same as the above post; only difference is that it gives 15% movement speed, which is equivalent of a free Phantom Dancer!

Typically, I like to get the items that apply to the game's current situation. If the team has lots of CC, Mercury's Treads are my first pick instead of Sheen. Why? You NEED those early game minion farms and levels. Mercury's Treads help you SO much when it comes to escaping a situation. 35% CC reduction is DEFINITELY not something to laugh about, especially laning against a Sion and Taric combo. Believe me, you don't want to, but it may happen ~.~

If you get mid because nobody else is fit for the job, DEFINITELY grab Ionian Boots of Lucidity or Sorcerer's Shoes immediately after Sheen. They will aid you massively in catching up to your opponent and either (A. Strike massive magic damage on them) or (B. make your stun cooldown so low that you stun every 9 seconds, making a kill nearly guaranteed).

If your opponents are all AP, buy Mercury's Treads.

However, if your opponents have only a very select number of people able to use CC and/or AP, definitely choose the CDR or MPen boots.

Moving on.
You typically do want to rush the Bilgewater Cutlass first simply you rely quite a bit on your AD early game, and then build the Hextech Gunblade. After, finish your Lich Bane and mount up some more gold for your Nashor's Tooth, which provides CDR and AS. After, make a MAJOR investment and buy an Infinity Edge, which will make sure your opponent is dead after 15% health. The last item choice will be explained below.

Item choices and why I picked them:

Lich Bane - AP + Your burst combo = DEVASTATION. The initial burst is around 1700, and if you can hit them with your auto-attack, it adds 300 damage to it. Extra burst item + a great stun to help you land the proc. Don't forget your Q spell; it can trigger proc too.

Sorcerer's Shoes - Definitely a great choice if you are willing to sacrifice CDR or CC reduction for greater magic penetration, makes your burst INCREDIBLE.

Ionian Boots - Will make your W spell go off cool-down in 9 seconds, while they're running away, have a nice sip of tea and Q spell them with a 2.5 second cooldown.

Mercury's Treads - You may want to substitute Ionian boots for these; CC is a big deal these days, and this will guarantee easier escapes. However, when the enemy team gets this, you are going to hate their guts.

Hextech Gunblade - This will spell vamp and life-steal while giving you AP and AD. A true hybrid's weapon. Plus it has a nice activation effect that can slow them down while your stun goes off cooldown.

Infinity Edge - Pantheon has a great passive that allows him to crit whenever they hit 15% of their life. Couple this with the lich-bane proc that will happen every few seconds, and you will 1-hit them if they even dare go below 15% life.

The last item is your choice -

Rabadon's Deathcap - +30% AP And +155 initial AP. Basically, this will make you a burst FREAK. You will spell vamp like CRAZY, and cripple any squishy that comes near you. Lich-bane proc will be 2x as effective with this item. DON'T be fooled by the first build, you will get around 600 AP with this item.

Nashor's Tooth - Not as good as Deathcap, but its CDR is amazing as well as the initial 55 AP and attack speed it gives. If you have a hard time spamming abilities, WTF you shouldn't be having a hard time spamming abilities.

Morello's Evil Tome - I don't really find this item THAT viable, because it has less CDR, gives 2 more MP/5 than Nashor's tooth, and 25 more AP than it as well. It only costs 115 gold less, too. I guess you could try it?

Rylai's crystal scepter - Use this if you want to slow with your Q spell. It'll annoy the **** out of your enemy champions, plus it'll add HP, making you an annoying BEAST.

Bloodthirster - Additional lifesteal + 100 damage? Holy ****, you will kick *** with your spear shot for sure. But it doesn't help Lich Bane proc and your initial burst damage.

THE SECOND BUILD IS A TYPICAL PANTHEON BUILD WITH A TWIST; Small amount of Spell vamp and Trinity force's 150% damage proc.

Please, leave feedback. I am pretty new to the build-making community, I want to see everybody's opinion on this build. Thank you VERY much for reading my build; and hope to see more hybrid Pantheons in this game.