The group is shown discussing how to drum up business after mistakenly shooting a child named Eddie on their most recent assignment. The enthusiastic imp Blitzo and his subordinate employees-Moxxie, Millie, and Loona-run an assassination agency called Immediate Murder Professionals (I.M.P.). Samantha Ames, Amanda Heard, Amy Heard & Lidia Liu
Vivienne Medrano as Keenie, Deerie, additional voices.James Monroe Iglehart as Vortex, Asmodeus.Alex Brightman as Robo Fizz, Fizzarolli.Maxwell Atoms as Ralphie, additional voices.Jinkx Monsoon as Martha, additional voices.As Medrano described it, while both shows share the same setting, Hazbin Hotel is about redemption and consequences, while Helluva Boss follows "characters and societies that already exist in Hell", with the main focus being on interpersonal relationships between characters. The show features a different cast of characters and a different storyline than Hazbin Hotel, another show created by Medrano, despite taking place within the same universe. With the help of an ancient book obtained from Stolas, a Goetial demon of Hell, they access the human world to complete their tasks on order from demons in Hell. include Blitzø (pronounced "Blitz"), the boss of the venture, along with weapons specialist Moxxie, powerhouse Millie, and receptionist hellhound Loona. (Immediate Murder Professionals), an imp-run assassination company in Hell, on their many different jobs.
The series follows the employees of I.M.P.