Helluva Boss
The story follows I.M.P. (Immediate Murder Professionals), a murder company in Hell. The members are Blitzo (pronounced "Blitz"), the owner of the company, Millie and Moxxie, a married imp couple, and Loona, a hellhound who is Blitzo's daughter. Blitzo also has a tricky relationship with Stolas, a demon prince. Stolas has a book called a grimoire, which I.M.P. uses to do their job, because it allows them to access the human world.