My opinion Runes help Pantheon a lot. His armor penetration helps with damaging the enemy champion hes trying to kill. His cooldown runes help also with reducing the time on his skills. His dodge is really useful to well of course dodge enemy attacks :D.

Pantheon's Ulti is very useful, its very easy to backdoor with it or if your really advance you can predict the enemys movement and chase them through that then of course W,E,Q combo. My personal combo is Q,W,E,Q because by the time the combo is done the Q will be done.

Pros
-Can do a lot of damage to one enemy.
-Very good chaser with his ultimate.
-Is really well being mid.
-Has a block when you hit someone/something 4x works really well.

Cons
-Can only target one target.
-Very useless if focused by the team.
-His stun doesnt last that long. (1.5 sec Max)

His ghost is very good at chasing or running away.
His Ignite is really usefull while fighting just adding on extra damage.

Pantheon is really effective early game, he is a really good harasser with his Q, try to spam Q as much as you can while Meki pendant will restore your mana while using it, while weakening them really bad you can just use your combo and theres a kill.

Pantheon is really effective mid game also, he can be a really good ganker while he takes out the champions on his lane, he can use his ultimate to go to other lanes to gank easily. This makes him really good in mid game.

This is were Pantheons at his best, when he has all his stacks hes just godly, he just starts to combo and gets a kill each time well.. depending on the champion lol. :D

I hope you enjoy this build. :)