I don't think it's possible for him to win, though (atleast not yet). I tried many times but he still can't win.
Edit: Wait, sorry. He can win.
Now IDK if this is true or not but this is based on what I did.
First you need to root for Xer to win then distract the other three. Distract with a conversation with Grushk and/or Rhot, and have sex with Roushk and/or Rhot.