Whats the optimal build for shaco?

Im currently 10-1 with Shaco, after losing my first game with him in ranked, im looking at my mistakes.

I couldnt keep up with the Kha, he was out deleting me vs my team mates, i mean they wernt warding... but thats not why im here. I want to get better with him.

Currently i got a "flexible" mastery/rune setup for him where i can build into either AD/Crit, AP, Attackspeed (split pusher/objective shaco), or even a suicide tank shaco if thats what my team needs (even tho that IS NOT optimal).

What i try to go for is >

(sometimes red smite, depending if i need that blue smite for someone like ez or lee who can out run me). Then into because the clone procs both the blood razor and hydra, making split pushing/killing dragon much much easier. The full build looks like> / / / depending on what the game needs.

Some people are telling me i just need to go full AD cheese shaco

Or the AP variant (or sub hourglass for ).

Whats your guys thoughts?

BONUS QUESTION!!!!

I have never even noticed this, but with shacos passive, he does extra damage from the back (UHH DUHHH), BUT, does his BOXS do extra damage from the back?

It says his attacks n abilities do, so i would assume the initial damage fear from the box does, but what about the auto attacks from said boxs?