If you want to see this build in action and/or want me to teach you to use it well feel free to add me. I'll gladly help you out. Sky1124 is my summoner name.

Based on giving Ez major AP, while also boosting his attack speed some and lowering his cooldowns by 25%, careful though this Ez is kinda squishy, but with his Arcane Shift you can jump walls, so do practice that, it comes in handy when ganks occur. Also when you get Archangel's staff you don't really have to worry about your mana, you regenerate it quickly enough.

Made to make your mana last in the beginning until you get Archangel's staff, and to escape ganks or catch up for the finish with flash.

Based on dealing your enemies major damage early on to get in those kills, to be built for later game. Essence Flux [W] is purely meant to deal damage to champs, and will not deal damage to minions at all, which is good when you have minions between you and the enemy champ cause you can fire a shot and not miss unless he moves or your aim is off. Your minion killer also a spell that with your passive increases your attack speed is your Mystic Shot [Q].

Basically, based on mana regen, and decreased cool downs. With a bit of support when you use clarity it gives your allies more mana than clarity normally would, along with decreased summoner spells, especially your flash.