EZREAL HYBRID

Well, to start off, I'm just going to say this:
I created this build thinking about the Ezreal players that can't make their mind, as you know AP Ezreal got nerfed, since then it hasn't been the same.
With this build you can have the fun of casting, but still have some pretty nice damage, being able to hit Mystic Shot with your AD and Essence Flux with your AP and do some pretty nice pokes.

You may be wondering why the masteries are 30-0-0.
Well, the answer to that is, Ezreal doesn't have a lot of survivability, therefore, instead of focusing 9 points of masteries in defense, why not just, since we don't have survivability, completely MELT our enemys with AP and AD before we die?

If you want to do changes you can, this is just a GUIDE to your success with my favorite champion :D

As for the runes, I pick them because:
Greater Quintessence of Ability Power - Self explanatory, give you some AP in the beginning to give more damage to Trueshot Barrage
Greater Mark of Desolation - Armor Pen, Giving more damage to Mystic Shot
Greater Seal of Ability Power - More AP, same explanation as the Quints.
Greater Glyph of Mana - More mana, to help out spamming Mystic Shot to diminish the cooldowns of your spells.

The answer is simple, In a normal fight where you can't Flash out before you die, you'll just feed, so it's more valuable to farm more without having so much damage with Essence Flux than getting killed a lot and ruin the game for you and your team.