He feels extremely similar to a character in a game I've played before (can't really remember who, though). His Q works like this: he has to hit two Qs, and then his third is essentially a Janna tornado he can use to knock up for his ult. Whenever he casts Q during E (his dash), it turns into a PBAoE like Zed's E, even if on the third Q charge.
He is strong, but people haven't figured out how to play him yet. I'd say the skill cap is definitely up there with the likes of Lee Sin and Zed.
This guy is the only reason I'm playing right now, he's really fun to learn and use and you can definitely get reactions to plays with W and E. I don't really have a set build pattern, but I go for Triforce/Shiv/Vamp Scepter in whatever order I feel like, and then start building tanky unless I'm stupidly ahead (like 5+ kills/100 cs), in which I'll just build ADC.