Maybe explain runes?

Armor pen is better.

@SmokedCarpenter:
Well now. This is something I can work with instead of "he's bad top".
I'll take this in to account with further testing. Thank you for your input :)
One thing I want to express though, is that I don't believe the relative strength of a champion should dictate if it is played or not. Of course this is true for high-elo, but then people playing at that level probably don't need to be reading these guides :)
But if everyone only played the (relative) strongest champions, the game would be quite boring, not to mention the meta would never evolve. I believe you should play the champions you enjoy playing. It is still a game after all. Champions played should be dictated by how fun you find it to play them. Anyway, I digresss.
This is how I currently play Pantheon and have had quite a bit of success with it. But I agree with your build choices and reasons for them. So thank you again for your feedback and I will experiment more :)

Yeah ignoring the fact that panth is not a strong top laner, that core is pretty horrid. Core should be merc treads/tabi, cleaver, randuin's.

Sunfire isn't as good as randuin's imo cause panth is more of a burst champ and the active helps him chase with spears or disengage, not to mention its teamfight utility.

Bloodthirster isn't core, panth is an AD caster not an auto-reliant champ, so lifesteal isn't priority. BT can be bought if super fed, but it's not core.

Mobility boots are not good on top lane panth. In the jungle, yes. In mid lane, yes (but more likely merc treads for mid).

GA is a good item on panth as like his 5th or 6th, but it isn't core either. Core means like the two or three items you should build first on him almost every single time.

Also a very important thing about masteries: Panth does NOT need attack speed! You should be getting the 5% cooldown reduction for his ult since it has such a long *** CD. It also helps your stun and E a lot too since they have decently long cooldowns early game.

Im just saying you shouldn't play him top, just like you shouldn't play some top champions jungle.

@Vynertje: You apparently didn't read the entire guide because I stressed that this is a top lane damage-based Pantheon guide. I also mention that I know Pantheon is good in the jungle and mid, but that's not what this guide is about. If you want to play him somewhere else, that's awesome, but there are other guides for that.

@CroatianKilla: Yeah, flask is also quite viable, but I'm going to have to test that more. Right now I find that the mana/life regen from flask is just too low and not as reliable as a regular pot. I'll probably update when I get more definitive results with using flask. Thanks for the input though!

I really like your guide, its really well writen and made. Nice job on it bro :D, but I think (doesnt really mean a lot) that you should start with a Flask because of his mana problems but its just my opinion

Pantheon jungle is kinda OP right now, but if you want to play him in lane it should be mid cause that means he has 2 side lanes to go and ult to. He's a really bad top.