after defeating Krubis you pick up a green Gatlian and pull the inhibitor chip out of him and he gives you the thumbs up

Yo what's cracking baby the name's Gus you can call me Papa Gus if you want. Here's what I can do I can shoot, I can shoot Discs out of my ass to stick to certain walls and I can suck up enemies armour so it's easier to shoot the shit out of them! Pretty sweet huh?

he said in your hand looking at you like he trusts you now since you rescued him from Krubis