Best skill for any fusion deck is duel,standby as you can draw into your fusion material fodder and spell easier. The gem knight build with volcanic shell and the pyro gem knight is best.
Master of fusion when you lose 1800 life points draw 1 poly
Jaden and aster Phoenix has it
I tend to run 3 poly 1 beast king of swamp 1 fusion sage. With mirror walls. This gives me usually a 1/4 chance of getting a poly to poly search in hand. Mirror wall with 1 payment is instantly giving one to hand if worse case it’s needed.