So after beezow's comment I had to rethink a bit my weapon concept.
As it didn't really make sense to shoot magic from a spoon.
So he needed at least one weapon (after watching the moves I think the off hand weapon can still not necessarly be strictly just a weapon).
So I made a wand and for fitting with my theme it will get a magic illuminescent potion, and use the shape of the snake to be close to the character last power.
So here is the WIP, I will pass it soon in zbrush