I've been wondering why I have been seeing people using Garen with carry build? Is it really okay for Garen to use carry build?
His spinning attack has the potential of doing critical damage every tick, which helps him to kill someone really fast. As a result it's fine, albeit not recommended. Garen is first and foremost a brawler/off-carry tank. Meaning he's the frontline, and makes sure no harm comes to the carry, or peels for the carry. However, if you really don't see your carry carrying (on the hand that he's braindead) then it's fine to build a carry build. Not recommended, more circumstantial.
You can build whatever you want on any champion. If you build carry, then you're going to deal... Tons Of Damage!
It honestly can work on Garen but you have to know what you're doing in the matchup or you'll suffer for it. His innate tankiness allows him to get away with building a shitton of damage but if you go against someone who is comfortable fighting Garen you might be in trouble. It's really good for stomping low tier players though.