@Jjsoups02
Panya Li is a hidden sim that is the default landlord for all residential rentals that are unowned. He shows up most in Tomarang but I have seen him in other places in my game wandering around in other worlds as a walkby. Since he's hidden, he doesn't show up in the Other tab of Manage Households so you can't just add him to a played household. But you should be able to call him and ask him over if your sim knows him.
I haven't taken a close look at him, but I think he's immortal. If you are not getting the move in or propose/marry social options when you talk to him, either your friendship and romance levels are not high enough for those social options to show up or he may have a hidden trait that prevents that because he has a specific role to play in the game similar to Grim Reaper and many of the Journey to Batuu sims. You can't ask them to move in or marry either.
Not what you wanted to hear, I know, but it might be impossible to make him a playable sim so you might want to find another spouse for your sim.
Hope this helps.