Kuroto

As Kelvin’s very first monster contract, this loyal slime played a crucial role in the protagonist's early battles, even assisting in the slaying of rival slimes from the start. Though originally a simple creature, the entity has since undergone a massive transformation into a Slime Gluttonia. Now possessing power that rivals the legendary Demon Lords, this evolved companion remains a vital, formidable force within Kelvin's growing army of subordinates.