Garen has always been that ***. no offense but he can be very annoying due to how everywhere he is. he is one of the most resilient characters out there. He, in my opinion, is most OP early game. Garen plateaus out end game. This build caters to his strengths and weaknenesses in that regard.

I got flat health to be even more OP beginning game
health per second runes to stack with his passive that makes him as resilient as he is, these runes are especially important to reduce trips to base.
Cooldown reduction runes as he is an only cool-down dependent champ. "the more you spin, the more you win"
Lastly Armor Penetration which i use mostly because its very universal between melee characters and works well on garen, being a melee champ.

REMEMBER!! although garen may have a select few solid core items always pay close attention to what your opponents have and build. About those core items, i always get a sunfire cape and i often rush it immediately after what is either my Merc's Treads or Boots of swiftness as it helps with farming creeps. boots: whether or not u got mercs or swifness doesnt make a big deal just select whats best for the situation, but dont get anything other than these two. After boots i make another decision to either get what is usually a FoN or sometimes a thornmail, again depending on the situation both are great items. I usually stay away from warmogs as there are better ways to spend that money. By now its coming to mid or end game time and your'e going to need some damage to keep up! i build garen all tank early game because he does a lot of stock damage already. However, end game your going to need some damage so i pick up a frozen mallet for the slow which works nicely with my next item yomumus. with a frozen mallet and yomumus's non shall escape.

Excellent early game
Remember to take advantage of your passive for staying in lanes it allows you to be more aggressive early game.

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Not so good late
[/list] ya il work on this later not done yet