Beelzebub
Even though the Wolf Curse said the being who'd killed Taros and occupied his body wasn't a Curse but a Taboo, Michael was still clueless. He asked multiple times what the difference between a Curse and a Taboo was, but his Curses didn't explain anything.
That irked him because he'd hoped his Curses would tell him more, but he still listened to everything else they said.
[Beelzebub is considered a god. An Infernal God, to be precise.]
Michael remembered the humans in the Tritan Alliance considering Eren and the others as "gods" but doubted his Curses spoke about the same thing. Gods weren't on the same level as ordinary Divine Lifeforms. At least, that was what Michael figured from the way his Curses talked about them.
"And how did a god – infernal or not – appear here? He killed Taros suddenly and occupied his body, just to disappear. That doesn't make any sense, does it?"