all you got to do is get all the ad bonus from the attack damage side then u should have six left after you put in all your ad runes(make sure u put 1 in the area that makes your summoner spells stronger) you want to the last 6 in the armor and Magic resist defense area.

for pantheons runes you get straight armor pen marks this will amke i so u can start hiting tru hits around lvl 3 making you hit hard. next you want to get straight armor seals, pantheon is very squishy the armor helps you survive against hard hitting ad champs who take top these runes plus your passive makes it so ad champs have a hard time killing you. then you want to get straight cool down reduction glyph they make it so you are able to use your q often this will help secure kills. then you want to straight armor pen quintesses for the same reason as marks.

when playing pantheon you want to make sure u get solo top in 3s and in 5s if you have a jungle you want to start by getting your q u want harasse the enemy champion top(in 5s your do the same but if u end up 2v1ing top then just tower hug and let them tower dive you then do the order of abilities on them) as much as possible at lvl 1. you do this by hitting the minions 4 times(kicking off your passive) then when u go to q them you will bock there ablity or attack and you hit them with out lossing life. when u hit lvl 2 use your mana pot to get to as high mana as you can dont use any spells wait until lvl 3 then(so now ur mana should be close to full) u want to wait till they come to harasse you then you use ur q on them then quickly use your w then e as fast as u can after that this will cause them to start to run use ur exusht then use ur q whenever u can while chassing them( if they dont run then fight them and use your abilities) then ignite them when they get low(note that you can tower dive them if u have enough mana to stun them, wait till the tower hits your once taking off ur passive then stun them with your w wihch gives ur passive back then just start hitting them and use ur q whenever you can you should be able to kill them with only taking 1 to 2 hits from a tower.(do not tower dive them if the have a jump or spin away also dont tower dive in 5s unless can see the jungle on map u dont want to get killed after doing this.

the first item u will get for pantheon is long sword and a mana pot, u then go for u brutalizer then u get berzerker boots then you get maw of malmortuis if the have a strong ap character if not then skip the maw and move on the next part of the build, u will then get the phage, then a vampric scepter, u will then finish the phage with frozen mallet, then u will turn your vampic scepter in to a blood thrister you will then get a black cleaver, then a infinite edge, then if you didnt get a maw of Malmortuis you will get a Warmog's armor