u/ALaserPointer

There are some additional things I'm not sure about, but the pet needs to eat a pellet(?) of some kind before being able to, it can't hold it's transformation forever, and at one point it turns into a helicopter (I think).

There are two more bits I'm really unsure about, but I think the main character has a robot arm of some kind, and there's some episode or moment about guardians or titans guarding a labyrinth that fall asleep at night (or day?).