@SquigglesJP
Unless there was a typo in the Japanese where I read it (on your scans), it's エルセーヌアント . So it ends with a "to" not a "do." (That is, unless that one panel has a typo and they forgot the " mark.)
As for what the names could be:
エルセーヌアント - Elseynaant, Elseehnant, Erseynant, Eirseynant. This name is made up, when you google it, only the comic comes up. I think my vote goes to "Erseynant" but they're all making best guesses of what is a very long gibberish last name.
カールニル - Caalniel, Caarniel, Kahlniel. I've taken a shine to "Kahlniel" myself.
エスベック - Esbek, or Esbeck like someone else said.
I'm looking forward to the next episode of The Bachelor: Demonworld Edition. 😂