Anon I genuinely could not care less about the guy. I don't hate him, I don't like him either. He's a plot device who's there to show Stolas' bad coping mechanisms, just like Dennis was with Blitzø. He's serving a purpose in the story, and I expect him not to reappear again except maybe as a cameo. He doesn't even have a name!
I do enjoy seeing the theories about him though, like people analyzing his design and why he might be at the party. For one, I agree with the people who say he probably wasn't even an ex or hookup of Blitzø's, and was only there either because 🤷 it's a Verosika party or because it was a great opportunity to be a rebound, whether that's with bad intentions or not.
But theories aside, I'm not interested enough in the guy to care one way or another. Just don't show me shipping stuff with him, NTR is a huge squick of mine lmao.

TLDR; plot device with cool fandom theories, that's about it