I would goku with B as kamehameha(chargeable), side B as rapid fire blast, up B is instant transmission where if used on the ground can be used multiple times fast and you can press A right after so that you can attack, down b as kaio-ken which he gets a new complete move set
B as kaio-ken 20x kamehameha, side B kaio-ken attack, up B instant transmission, down B explosive wave which can reflect attacks and can attack. Final smash = super sayin B as kamehameha full charged kamehameha = supersayin 3 kamehameha, side B as meteor smash, up B as instant transmission, down B is sprit bomb but it cancel supersayin