This build for the way I like to play Pantheon. If you are into a more damage based Panth, then look for a different build, I like to play him as a Tanky DPS that does a good amount of early game damage to help get him his items.

The runes I like to use, are more of a Jungler style of runes, that help make him tanky better in the early to late game.

Taking Armor Pen Reds and Quints for a good amount of damage once you get you Bruta. Others you could use would be like Damage Quints, or even HP to help early game.

The Armor Yellows, are for mostly early game where you are going to die most likely to a straight up damage champ, not so much a Mage. You could use others here if you wanted, but there is not many I would suggest to use.

Now for Blues I like to get MR per Level to help out late game since the build doesn't get any Magic Resistance at all, except for a optional item I will explain later. Cooldowns are the only thing I would take here instead.

I go a fairly standard 21-6-3, to maximize damage that you may not get mid game. Going more towards Crits, Armor Pen, Damage, and Cooldowns. The Defense Tree is to help with Armor and MR early game, and the Reduced death time is from when you may need to respawn quicker, could change a game.

It would be possible to go 9-21-0 if you wanted to be a bit more tanky then usual, but I prefer the damage.

For summoners I take Ignite and Exhaust. These will help it taking down champions early game to get your items better.

You could go different combos, like Flash Ignite, Flash Exhaust, or even Ghost Ignite if you wanted to, depends on play style.

The reason I don't take flash is because you really do not need it. It can be helpful to get away, but remember he might as well be a Spartan, Die With Honor.

Now for Items, I go a Tanky DPS style. Taking some early damage with a few Doran's Blades and a Bruta. Then going more tanky with Frozen Mallet to help chase after enemy's, Warmogs for a health blob (but with you runes and masteries should be hard to take out), the Atmas's for a good amount of damage late game when you get it, then finishing Youmuu's last so the armor pen doesn't go to waste.

Other options I would suggest for items: if they have a lot of Magic damage early buying a Chalice of Harmony would not be a bad idea. If they have again, if they have a good amount of Magic attacks, building a Banshee's Veil could help. Other damage items like Blood Thirster, Black Clever wouldn't be too bad if you need a lot of damage.

One item I would like to point out to consider getting on him, would be a Trinity Force. I would only suggest getting this if you do NOT want to get Frozen Mallet. There is no point to getting them both, the reason you would get either is for the HP and slow. The reason trinity would be OK to get is the Sheen proc for extra damage.

Some people would argue that getting Manamune on him is really good, I beg to differ. If you really need the mana regen get Chalice of Harmony, it will make you more tanky, and it gives more mana regen the Manamune.

After setting things up, get ready for some action.

From Levels 1-6, Pantheon can put out so much damage, by harassing with Spear Shots, and by using Aegis to stun and combo up with your and your laneing partners spells. (if you have one)

From Levels 6-11, Just farm up and get kills by supporting teammates with your Ultimate, and stunning for extra help. Getting either buff around this time is great on Panth to help slow and damage with red, and more Mana and Cooldowns with blue.

From Levels 11-18 Do the same as above, you should be quite tanky by this point and be putting out enough damage to solo anyone on their team.

If you wish to play ranked with Pantheon build, there are some different items and ways to play you may need to know.

For Items: Some key items include Banshee's (included above but very imporant in ranked play), getting more armor and MR is very important, so like Sunfire Cape, Force of Nature, Randuin's Omen, and Quicksilver Sash. All of those are really good in ranked games.

For gameplay, Pantheon is a great solo top vs. another solo, he is not very good 1v2 in my opinion. In a 1v1 lane you can either be really aggresive, or very passive.

Playing aggresive is very fun, it is possible to get Aegis much earlier (at 2 instead of Heartseeker) Stunning, Spear Shoting, and basic attacks do a lot or early game damage.

Playing more passive, is letting them attack you, stunning and doing damage, but focusing more on farming if possible.

So with this build you should be able to do a lot of damage early game, tanking lots of hits mid game, and completely destroying late game. If you have any suggestion let me know, and if I like them I will add them. This is my first build