You cannot use “Change of Heart” on a face-up “Mataza the Zapper”.
If you take control of a face-down “Mataza the Zapper” and flip it face-up, it stays on your side of the field and doesn’t return to the original controller.
If you use “Monster Reborn” on “Mataza the Zapper” while “Remove Brainwashing” is active, control of “Mataza the Zapper” does not return to the original owner.
While “Skill Drain” is active, you can take control of “Mataza the Zapper” from your opponent.