Not that you have any idea how to play Pantheon.

Unfinished, way too short.

It was looking relatively alright through the cheatsheet (nothing really worth an upvote, though) but then I started reading the guide, and I was like, 'where's the information?'.

You didn't unlock your 7th item slot yet? Lol nooblord scrub, uninstall now.

So you have 7 item slots?

This is a pretty mediocre guide. In most situtations, Mercury Treads > Ninja Tabi. You should only get Ninja Tabi if you're against an AD champion and you're losing hard. Also, add Boots of Mobility as an option. If you're roaming, they are a very good choice.

I suggest Rejuvenation Bead + two Sight Wards + three Health Potions + one Mana Potion for the starting items. You don't have as much early damage, but Sight Wards let you see ganks coming, Health Potions give more sustain for a while, a Mana Potion lets you harass with Spear Shot more often, and a Rejuvenation Bead gives a little bit of sustain early on, and can be built into Warmog's later.

I know the skill order is wrong haha i just created this guide i changed the skill orded sry for that :P as a good pantheon player i never had this skill order i messed up but its fixed now ty for the comments

^as a panth player myself I have to agree with the above, skill order is wrong. Now there is a debate (albeit a small one) on whether your Q or E can be the most effective, but overall that is up to the user, pick your choice and stick with it. I also disagree with your item explanation to a certain extent. Frozen Mallet and Spirit Visage are not necessarily "must have items." Your match up/counter examples are not always true as well, I have, and also have seen Panths destroy a couple champs you have listed. Please review and add a more thorough explanation of your skill sequence, items and counters. Reserving my vote until then.

You screwed up on the skill order. Basics dude. Not only would it be in the wrong order in the first time, but you didn't max Q first. Super short guide with bad use of coding. -1

Cheatsheet
Runes look fine, items are acceptable (personally I prefer some mana regen for Panth but to each there own). I disagree with Item Sequence, E is more important level 2 because of the crits it gives. But I guess it depends on who your jungler is, and if they can provide early game damage during ganks. Not maxing 1 skill first is a huge mistake, due to the way league skills are balanced. Masteries look fine.

Pros and Cons
Pantheon is tied for the highest base MS in the game, so I'd suggest removing or rewording the part where you say he has low base Movement speed.

Counters
Would be nice if you added a little numerical ranking of how easy each of those lanes was, but not absolutely needed.

Summoner Spells
You say Heal is good for surviving, but then say Barrier is bad. Barrier is better than Heal in lane just in terms of numbers, and only marginally worse as the game progresses.

Final thoughts
A fine guide, but needs a lot of work adding content and explanation on all things. Skill Sequence explanation for instance is missing, as is alternate items and explanations on how to lane and teamfight. +1 with the request you keep working on this.