SSJ4 Black vs SSJ4 Goku

[Nèro]

Hypothetically speaking, let's say Black goes ssj4 during his fight with Goku. Goku also decides to turn ssj4. Who wins?

 

[Let's Go Fearless!]

Black would murder him.

 

[Flame]

Black would destroy. Goku fought even with him as a Super Saiyan 2. Seeing as how Goku Black is still Goku's body the will most likely receive the same boost. So Goku Black would demolish Goku.

 

[Captain Cadaver]

Same as said above. Black's far from his limit right now, yet is confident in surpassing Goku and seems to have access to the growth rate of Goku's body, especially seeing as how he's set to attain "Super Saiyan Rose". His latent power ought to surpass Goku's even if it were by a minimal amount.

This is assuming the SS4 in question is a hypothetical post-God SS4 Goku. If it's GT Goku, Black oneshots him.

 

[Spiral-Force]

Assuming this is DBS Goku (current): Presently, Black's potential is distinctly greater than Goku's, so Black would win if they fought as SSJ4's.

Assuming this is GT Goku (limits surpassed): Base Black finger flicks SSJ4 Goku out of existence.