Ultimate Warrior’s short stints in the late 90’s?

Why was the Ultimate Warrior's return stints so short in the WWF in 1996, as well as WCW in 1998?  Am I to assume that in each company was Warrior being his usual nut-job self, or did each case differ?    

In 96 he was basically using WWE to launch his "Warrior University" and comic book deal, and when Vince stopped promoting those ventures and also (allegedly) promised him a World title reign and then reneged, Warrior stopped showing up.  In 98 with WCW, it was actually just a short-term deal and the intention all along was to get the Hogan match done and then both sides would cut ties.  Granted he was still nuts, but no one ever expected him to stick around.