Oh hey I just watched some of the video you put a link for. I thought you needed him to swing like an actual wrecking ball.
Watching the video, I think you don’t need anything special!
You just need to have a way to switch some of his Character Movement parameters when he switches to ball mode, and have the ball animate/spin to pretend it’s rolling instead of what’s really happening which is just him walking but LOOKING like he’s rolling, and his Ground Friction and Deceleration are just switched to lower numbers while in ball mode.
So he doesn’t have to actually roll like with physics, he can just Walk while doing a rolling animation or spinning the ball mesh proportional to his velocity.
Do it this way and the network replication will be automatic and smooth for the character movement because CharacterMovement is coded that way in the engine.
BUT WAIT: I watched the video further and he does have a swinging grappling hook motion.
I don’t know how to get that working smoothly over network. But someone else does. A few people on here have done it.