Well.. There is no real reason you should play AP Garen, but when you want to surprise your friends with a fairly decent AP Garen that can still murder your nooby friends (Who think AP Garen is nothing but stupid) then youre were you should be. :P

DON´T DO THIS IN RANKED PLAY, unless you are a GOLD or higher player whos smurfing in Bronze!

Well runes are pretty standard.
Glyph of scaling magic resist, for the defense against AP carries.
Seal of armor, for the defense against AD carries.
Quint of movementspeed, for the extra chasing ability.

Only one thats strange is the mark of magic penetration.
This one helps the damage output of your ult by a lot, and since you are going to be using it A LOT, do this.

Pros
- Most unexpected build EU/NA/Or whatever.
- Still does some decent damage for a total troll build.
- Its Garen AP. Everybody thinks youre a badass if you do good.
Cons
- People think youre a total idiot.
- No ap scaling abilities.
- Does less damage then dps Garen.
- People will rage if you do bad.

Starting Items: I mostly start with these items. Elixir of fortitude for an easy early kill. Garen doesnt really need any health pots, because of his great passive. Get 1 ward to be safe from jungle ganks and a kill is ensured!

First Back: Assuming youre already level 6, the sorcerers shoes will be a great buy for your ults damage. Also get the stinger for that cooldown reduction and your increased damage output with some attack speed. Be sure to keep spamming your Q to constantly poke your enemy top laner. Also gets some more wards to be safe from ganks.

Core: These items are ESSENTIAL for AP Garen to kinda work. The sheen gives you a decent attack bonus after you used an ability and the nashors tooth makes your basic attacks do some more damage.
Also the only reason you should get Deathfire grasp is for the epic combo possible.
Step 1: Use Q)
Step 2: Use the active of Deathfire Grasp
Step 3: Ult (If hes not dead yet, follow it up with another Q)

End Build: If the game continues into Late-Game or if youre just fed, you should buy a lich bane next, for even more damage after an ability. Then buy a wits end for more damage with your basic attacks and some MR. You´ll also need some armor, so buy a zhonyas (Active also works great on Garen).

This is the ability you will be using the most in lane together with Judgement. Use this to poke your enemy top constantly with a ****ton of damage(if you have sheen) and continue with Judgement for the highest damage output.

This ability makes Garen a lot more tanky. Since your an AP caster (Sort of), this ability is great, cause of the fact that most AP carries are squishy.

Great minion clearer, use this anytime you can to get the most gold possible (and damamage output)

Garen Ap is mostly build around the finishing up with your ult. The damage you achieve when you first use deathfire and then ult is just ridiculously high. Try doing this as much as possible, but only when youre ensured you´ll get the kill!

Mostly Garen ap is based around basic attacking (Dealing magic damage) and your deathfire-ult combo. My advice is, please dont use this build when playing ranked or with strangers in normal (Unless youre a **** like me and still do it). This is a lot of fun with a premade 5 team if you get fed.

Hope you enjoyed reading this guide. And tell me what you think!