Just Imagine Gun God Rumble!! ....
Rumble: Let's get in the fight!
Rumble: Let's get in the fight!
Mech God Rumble if anything, since he isn't switching/using different guns.
That said since Ultimate skins are one of a kind it would seem weird to make a similair skin for Rumble.
So what about Mechmaker Rumble, where you can customize your mech, so instead of switching the whole form you would only switch components and mix and match them around?