Desco accepts the name without comment, mostly because she's used to weird names. Like Nintendon't.

"Desco's full name is Death/Extermination Submersible Combat Organism Kazamatsuri! You may continue to call her Desco, though. And if the people that rule you show up in the city, that makes them Desco's subjects, which would make you Desco's grand-subject! So it's easier to just accept Desco's absolute dominance in all things, because it's inevitable. Don't worry, Desco is going to be a claws-off tyrannical overlord, because she is busy figuring out how to conquer the Netherworld."