Who could be the best for Bonnie between Kai and Klaus? and why?
Well, history aside, considering only personality and chemistry I think Kai would be a better match for Bonnie than Klaus.
Kai (beside all the psycho stuff) is fun. He makes jokes, he knows how to have a good time. Bonnie could use some fun and there would be sparks between them.
I don’t think Klaus and Bonnie match on a personality level. But it’s an impression that I have. Maybe if we had gotten more interactions between them I would have a different opinion.