This guide is just a show on some random thoughs and some builds I've used in the past that they worked for me! These are sort of random so its not a guaranteed success!!! But sure those can be used for fun and experiment and thats the primary reason of this guide.Enjoy!

WARNING!!!!

This is a guide for experiments! Vote based on imagination and the overall project. Feel free to use the builds and tell me your results and thoughts!.We might acctually discover new ways of building and playing this char :)

I decided to make this guide because if you play with the same char you become a bit bored and i hope i can give some new ideas in the field.Sure many of those builds are familiar.
The names i've given to the builds are:
-Manadrunk
-AltQQ build
-The AD Variation(this build is inspired from the AVAST!Biglewater Pantheon which you can find in the Similar Builds list.
-Grenade build(KABOOMM!!!)
-Meat Shield!

So lets get started shall we?? :)

The idea for this build came because many people have serious mana issues with Pantheon and they like using Manamune on him so i though that i could make a build based around it!.This build combines Extreme amounts of mana as well as good resistances and health!.I use items which will increase my mana(thus giving us more AD from )and increase the overall survive ability!.
With this build feel free to spam your abilities(after you have the tear of course :D).You want to stack up the mana from as fast as possible to get the maximum effect of it!.So harass constantly and farm with as much as possible!.Use it almost every time its ready.Also you will be able to use your combo(SS+AOZ+HSS)much more often.Harrass them to death!!!!.You end up having 3,1k mana witch is all converted to AD making you crush enemies!.If you like spamming your abilities this is the build for you ;)

The final AD with this build reaches up to 336 AD and 40% Armor penetration

Damage:3/5
Survive ability:4/5
Effectiveness:3/5

Pros:
-Good amounts damage.
-No mana problems anymore!
-Hight resistances.
-Endless harassment!
-You i'll never get oom even in the longest teamfights.
Cons:
-Many people dont like using .
-Lower damage in the early game than other variations.
-Need to spam always to have fast the mana bonus which might be boring after a point.

The name of the build just came to my mind because many people like to target Pantheon always and this build will make them **** their pants!.This is an offtank build based on the Metagame style.Hight resistances and good burst provided by .You will be dealing less damage but this is not the point.As an offtank you dont aim for maximum damage but great survive ability and soak damage.Early game you will do hight damage as all Pantheon AD builds but as the game develops you will be tank's best friend!.You will protect your carries and charge fearless inside the enemy ranks!.If you have a good support behind you you will be like a moving wall bashing onto their faces!
In order for the build to work you must alter the playstyle a bit to use to its full potential!.You wont be using the classick pantheon rotation.You will most likely go: +autohit+ +autohit etc.You will be using mostly to get the proc from up.
As you are an offtank be ready to charge in the fight second or even intiate it if needed!.
This builds combines extreme durability and 232 AD as well as good soak damage.You will be able to kill any shquishy carry that way as you did before!.Be afraid of NOTHING!.You are a Spartan god dammit :P

Damage:2,4/5
Survive Ability:5/5
Effectiveness:4/5

Pros:
-You smash people who think you are fragile!.
-Triforce works wonders!(ability+autohit)
-You can still deal some nice chunks of dmg.
-Fast movement speed.
-Your melee hits will do damage good as any other offtank so stay and hit!
-You are now more able to change the fate of a game.
Cons:
-If you want a build to kill people wih just one HSS this is not the build for you :/.
- Does not help Pantheon as much as it does Lee Sin or Irelia early game.
-As any offtank you have to farm like a GOD to finish it fast.
-Not sure if i would prefer having a Pantheon offtank instead of an Jarvan offtank...

As i described earlier this build is not 100% legit.I was inspired by the AVAST!Biglewater build.He was the first to post a build for Pantheon witch was using and i realy have to congatulate him for it!.This build is a true MONSTER of damage!.Especially if you get fed in the begining you can dominate during the whole game.You will be using the standard Pantheon rotation and wreck peoples faces!.Try to land your heartseeker on as much people as possible!.Crush the enemy team!.And by using you will deal deadly damage to ANY tank who comes to your way.
The reason i have this build here(in an guide for EXPERIMENTAL BUILDS)is because its not 100% my build and because a lot of people think that is a bad item choice for .This is a chance for this to change :D.

The damage with fully stacked 's reaches around 419 pure AD

Damage:5/5
Survive Ability:3.5/5
Effectiveness:5/5

Pros:
-Insane! damage.
-Good amount of health.
-Your spells heal you as well(and quite a lot acctually).
- makes this build truly OP.
-The way you burst people is truly addictive!
Cons:
-Expensivvv...
-You sometimes overextend cuz the damage you have makes you think you are invincible.
-There is a gap when u make where the build does less damage than its supposed to but the problem gets fixed right after you get .

This is the build i started using with Pantheon between 20-30 lvl.I was playing quite suicidal having + as my summoner spells since i was always pushing for fist blood as any Pantheon should do!.If i managed to reach around 3-5 stacks early game i was unstoppable!.These where the times when Pantheon really owned people(before the ugly nerfs).I wasnt really conserned about survive ability back then since i was killing people so fast that they never had enough time to kill me.But as the levels go on and on its not that effective against skilled players or if your enemies where playing defensive and you couldnt get enough kills early on you whrere on disadvantage.Also with no escape mechanisms available it was a kill or get killed situation.Still i though i should post this since this worked pretty well in generall and it may help new players get the upper hand and have some good time nuking people :).Still if you are laning with a premade friend this is a very viable build!.I just dont really recommend stacking items.You die once and lose so much power that its not worth the risk.

Final AD 443+.If you are playing ranked this build is not recomended!

Damage:5/5
Survive Ability:1.8/5
Effectiveness:3/5(depends on the situation)

Pros:
-Strong Early/Earlymid game.
-Facemelting AD
-Can make people ragequit early game.
-Characters with no cc dont stand a chance against you(Miss Fortune etc...although depends on the player)
Cons:
-Very risky.
-One wrong move and you lay dying.
-Uneffective against good players.
-Any kind of cc will probably be your end.
-Can panic if you cant get enough kills/assists.
-Stacking items tend to make people rage hard and killsteal.
Its up to you if you want to use this build or not.I for once recommend it only for low lvl players.

God how many times i've won with this build!.I usually do this when i dont see people picking up a tank(witch is quite usuall when playing random).Or when i see that our tank is no good :P.This build is not having the best damage you will see nor the most Survive Ability.But its effective and makes you super bulky!.You cant be bursted down!.You can make a Leblanc cry in agony!.But i've seen this build around again i hope i wont be called a stealer or smthing.I first used it like a year+ ago :P.Anyway this build needs good farming so you can use Atmas to its full effectiveness.Witch is around 80 pure AD with 4k health!.this build gets better and better with time.When its completed its face melting.You are not a tank since you lack some resistances but you are extremely bulky and able to take much more punishment than other Pantheon builds(glasscannon).You can play as an offtank but you are not undying or smthing!.You cant be reckless or charge alone and stuff.Cooperate with your team and Heartseeker their team hard!.Just remember:You are not a Tank!!!

The final AD reaches -300+ combined with 4+k hp you seriously are a threat!.

Damage:4/5
Survive Ability:4/5
Effectiveness:4/5

Pros:
-Well balanced build.
-Able to perform many roles.
-Effective and trustworthy.
-You may be able to intiate small fights(depends on enemies).
-The carries will still fear your spear.
Cons:
-You need to complete the build to be devastating(since Atma is your damage)(you cant get Atmas after Warmogs because you have a HUGE gap in AD before you complete it).
-Kog Maw will eat you alive.
-You cant always follow the exact item rotation since the situations can change rapidly.
-Tend to feel like god witch makes you stupid things sometimes.

Dont and i mean DONT use this build if the opposite team has Kog Maw.He will melt you!.You can bear the 4% dmg from madreds but NOT from the 10% from Kog.Remember that.

So this is it :).I hope you enjoyed my guide and i would be glad if i was able to give you some ideas about our Stanpar fellow.

Feel free to comment,any feedback would be much aprettiated!.Thanks for reading :).GL & HF!.

Updated.

16/02/12

Small changes in all builds in item purchases, runes and masteries.The icons inside the guide have not been updated yet though.Enjoy :)
During to the consecutive nerfs to Hextech Gunblade the build has lost some of its power, but its still very fun to use.