[ Honestly, he thinks that the frown is her trying to think about and figure the whole thing out more than her actually frowning. ]

Well, I don't know much about being a retainer, but I guess it's kind of like that.

[ How did they go from him saying that he tries to be a friend to her asking about the perks, though? Though that's because Shizuo never thought about what he could get about the whole arrangement between gods and shinki. ]

Having a friend you can trust and work with...? I mean, I don't know what you count as a perk. Shinki all stay with the gods they're assigned to, so in a way you're taken care of by the god as much as you take care of them.