This is my build and so far i been winning almost every game with this build. i will now explain why the summoner spells the runes and items....lets starts!

Exhaust- with Pantheon having exhaust it is very easy to control a fight for example, i like to work people down with my spear attack and as panth you can leap in on your "w" exhaust the other enemy and if you time it right you just got a double kill!

Ignite- I picked this because TOO may times have i just about killed someone and they escape with under 20 health! Ignite is a great tool to aid you when you are going for the kill when you jump in the fight with your "w" if its a single target you should use "w" say one Mississippi throw exhaust and your ignite up and they are dead!

Runes- i like armor pen makes your spears very annoying to the team! and i pick MR and Defense because if you use this build they will try and focus you and realize pantheon is not dropping fast and is still killing me! Also for this build panth doesnt attack fast i make him a harasser with his spear then when they are about 40% health you can take a easy kill

Items!
why go with phil stone? well health regen and mana regen and making money for having it seems like a no brainer! you get your mana back from throwing many many spears and you can stay in a lane and farm minions better! think about it if you have mana regen you can waste a spear or two on minions to get that extra gold without having to worry about mana!

Merc's Threads- from playing panth i see too many people try and stun me when i go in to stun! so how is see it is A) you're AP stun didnt hurt and B) im not stunned anymore and i just killed your friend

The Brutalizer- i love armor pen! and early game with this bad boy with those runes you're spear is a PAIN and does very good damage!

Phage- Well now you got some health and slowing people down! you will be surprised to see the number of players that will run from you! you stun them and slow them and stun them and slow them, They just dont learn! but easy kill for you

Vamp scepter-Life steal nuff said! haha makes you live longer in a fight and it WILL save you're life! after you start owning it comes in play very nice!

B.F. Sword- you have items that give you damage and armor pen, now it is time to become a bigger pain and have that spear and heart seeker doing damage!

Frozen Mallet- More health constant slow makes you useful in team fights and escaping people or chasing them down!

Black Cleaver-mmm armor pen!! now you are annoying with this item! if you get this far in the build you are either carrying or getting a lot of easy kills.

Blood thrister- just start laughing here! there team is saying "omg now panth has a blood thirster! we are dead!!"

Well you will notice that this is only 5 items, the 6th is up to you! these 5 items will lead you to victory so have fun guys and girls and i hope you like my build! This is my first one and if you liked it please give me a comment letting me know about you're epic wins! and if you have any request on other champs please let me know!