Talk:VPBE/@comment-24795478-20150414033805/@comment-35229418-20150418114330

If you build Youmuu instead of the current Black Cleaver you're trading 20 AD and 200 HP for the crit and the active (stacking 5% ArPen has about the same value as 10 flat ArPen on assassins). This means that if you build Youmuu it's for synergy with your build. Zed gets it because of BotRK, to get more autoattacks. Talon gets it because that makes IE an option later on. Riven alternates skills with autos, so even just 15% crit chance helps.

AS and crits, like you said, are for autoattacks - when I say caster I mean someone that usually gets in 2 autos and uses skills as their main damage tool (like Kha'Zix). I wouldn't call it a pure AD caster item because it also does other things (though it is good for casters right now).

(Though when I look at winrates I see Kha'Zix has a higher winrate with Youmuu than with Cleaver. Granted it's 30 games vs 3,155 games, but I think it's worth a try, since Cleaver is being changed anyway.)