Hey all! Hope you are well

I wanted to ask about achieving a "body swap" gimmic. I want to build a character for the workshop that is essentially a "Captain Ginyu" to the Aether universe.

The idea was the OC swaps with the player/CPU character, but unlike Ginyu who harms his own body before switching, they heal both themself and the opponent to a fair degree for a fair fight. Also akin to Manaphy's Heart Swap in Super Smash Bros. Brawl.

My question is how does one go about properly implementing it? I have a basic idea. But code wise is where I am struggling.