Can someone please tell me who is the main couple?

My guess is the ghost guy is the ML. IF he Were just a side charakter they would not revive his body in the plot. And since he can posses soneone’ s body as a ghost there is a possibility that he will get his body back and will love with MC happily ever after

From comments before it's wu sa ut I'm not sure myself

It IS Wu sa. The author confirmed it I think

I secretly want the blond hair guy

I wanted dit to be a poly relationship Or js the mc ending up with all 3(possibly 4)