I definitely think Yuber could push Hawk into Berserker! You said once you played Yuber before so as you know the dude likes to use as much of as his strength as is necessary to defeat an enemy while still providing himself a thrill...and no more than that. So escalating in power usage could definitely be a thing.

Hawk would probably be able to tell when Yuber isn't giving it his all. Dude isn't subtle about it.