Player can transform into Wither Storm. He will get abilities, pull the target, follow 1 target, send sickness, tighten certain blocks, poop(jk)? Can release the target, and other.

Are you trying to make this compatible with a Morph Mod or actually make it a feature of the mod itself?

Feature in mod

This doesn't really fit with what I want for the mod, and would be a lot of effort to try to fit in.