I'm Padrepio 69, a gold ADC player on EUW. I was addicted to old blue Ezreal, but during s5 he was not playable anymore IMHO. That's why I love this change on Black Cleaver, that should solve problems.
I'm sorry for my english, it's not my native language.
This guide is still under construction. I'll update as soon as possible.

Thanks to jhoijhoi for How to make a guide

Pros

+ Good early&late game + Can kite forever + Free flash every 4s + Global ultimate

Early game is where Ezreal shines: as AD caster, he can deal damages from safe with Q and avoid engage with E. But with this build he has power also in late game: when he reach CDR cap he can spam Q every 2 second, gaining Iceborn Gauntlet and Black Cleaver procs on hit. Thanks to that he has a lot of movement speed, while opponents are slowed. If someone catch you, you can always Arcane Shift away 'cause your Q reduces CD.

Cons

- Need objects to be effective - Everything is a skillshot - Maybe hard to master

This build is all around 3 basic object, and you need those to do something effective. If you don't get kills early, you can feel your mid game lack of damage uncomfortable. Fortunately, as soon as you build your core items, your damage grow up.