Jesus, up there with old favorites like Pudge and Invoker.
Why is Legion so high on pick rate?
everyone wants to be a hero.
same reason pudge always had high pick rate.
Slark only has a 52% win rate.
http://www.dotabuff.com/heroes/winning
Problem is he's picked 26% of the time.
well... he is fun to play but not as easy as some might think. not a typical noob-friendly or all-around carry.
but honestly, those stats are meaningless. you can't group very low skill with very high skill and make percentages out of all those games combined.
http://www.dotabuff.com/heroes/meta
organize 5k+ by pick rate. he has the highest pick rate and barely 50% wr.
why he has those stats is anyone's guess but I'd choose other heroes fatigue and counter to some patch darlings (like potm) above him being op.