Geno

Geno is a Star Being from Star Road who serves a "higher authority." He once possessed a puppet in order to aid Mario, Peach, Bowser, and mallow to stop Smithy from taking over the Mushroom World and filling it with weapons.

Mecha Sonic Saga
A little before the Subcon Arc, Geno was sent to Subcon after hearing that the tyrannical frog king Wart and his 8-bits were once again causing trouble in Subcon. Geno managed to defeat the 8 bit crew, but Wart knocked him out from behind. He then took Geno and brainwashed him, making him the newest member of the 8-bits as a result.