Hello! Welcome to my Pantheon guide. I see Pantheon as a hard damaging bruiser-buster. What makes him a so good champion is that you usually lane him on top against high hp bruisers like tankplank, olaf, volibear etc. The reason I think he counters bruisers is that he gets those 100% crits on early. He can also be built as a tanky initiator. As tanky his ulti works really nice in teamfights, both as an initiate but most important is that it shatters the enemy teams positioning because it forces them to move away from it.
As hard hitting pantheon I use these runes: http://www.mobafire.com/league-of-legends/rune-page-planner#&rune=267:7-329:2-271:9-343:9-257:3. The cdr to reach the cap and the lategame ad is needed for high dmg. As tanky pantheon I use these runes: http://www.mobafire.com/league-of-legends/rune-page-planner#&rune=317:9-265:9 + the hp% seals and quints because hp stacks so nice with atma's impaler.
As ad pantheon I use these masteries: http://www.mobafire.com/league-of-legends/mastery-tree-planner#&tree1=1-3-0-0-4-4-0-4-1-0-3-1-3-0-3-0-1&tree2=0-0-0-0-0-0-0-0-0-0-0-0-0-0-0-0&tree3=1-0-0-1-0-0-0-0-0-0-0-0-0-0-0-0&v=2 but as tanky pantheon I use these masteries: http://www.mobafire.com/league-of-legends/mastery-tree-planner#&tree1=1-3-0-2-0-0-1-0-0-0-0-0-0-0-0-0-0&tree2=0-3-3-0-4-0-2-1-0-0-1-3-0-0-3-1&tree3=1-0-0-1-0-0-0-0-0-0-0-0-0-0-0-0&v=2
For ad pantheon I start off with boots, a ward and a hp potion. I go b when I have over 1800g and purchase cdr boots and avarice blade and buy wards and pots for the remaining money if there are some. I rush trinity force and then infinity edge. My final build looks like this: http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=113-63-46-101-60-60 but if you face an average of magic damage champions , purchase a Hexdrinker after Ghostblade. But if you face an average of physical damage champions , purchase a Wriggle's Lantern after Avarice Blade. And if you face champions with good stuns and snares, purchase a Cloak and Dagger.
For tanky Pantheon I start off with boots, a ward and a hp potion aswell. I go b when I have over 1675g and purchase Ninja tabi and Heart of Gold. Ninja tabi is really good with pantheon because it works nice with his passive. I rush Frozen Mallet and then Atma's Impaler. My final build looks like this: http://www.mobafire.com/league-of-legends/item-purchase-planner#&item=53-41-36-76-102-65 but if you face an average of physical damage champions you can purchase a Sunfire Cape instead of Banshee's Veil. And if you face champions with annoying stuns and snares purchase a Cloak and Dagger after Atma's Impaler.
I usually use Flash and Exhaust on Pantheon but you can also:
* use ignite if facing enemies with annoying heals
* use heal instead of flash if you simply don't like flash
* use smite if you try jungling (then run ad build with wriggles) which I don't prefer
* use clairvoyance if you don't have a support, ashe or teemo or if your support refuses to use it.
* use teleport if your playstyle includes ganking more then farming.
Pantheon is a great dualist and dominates lane when fed/farmed like few other can do. Having a often ganking jungler for example udyr that can stun in your Heartseeker Strike. And having a shen in bot/jungle can really make your team have the advantage in all situations with teleports and great mobility.
Don't use heartseeker strike on minions if you don't run around with full mana and has no one enemy on lane to use your harass combo on. (Heartseeker Strike does decreased damage to minions)