This could be completely wrong, but wouldn’t Kai’s death as the leader of the Gemini Coven kill everyone else in the coven, ie Lizzie and Josie. I know he died in season 6 of TVD technically and now he’s “not alive” as such, but then again this is the TVDverse so anything could happen. Providing this was true, this would mean that Kai wouldn’t REALLY be dead, maybe an illusion spell or something idk, which would line up with what Chris Wood said about wanting to come back to play the character for as long as possible.