Roddy Piper
Vince McMahon’s decision to break the territory rules was what changed the wrestling business. Piper was one of the superstars who was jumping across the territories. Vince, however, changed this and signed Piper to WWE and made a star out of him.
One of the reasons for Piper agreeing the deal with WWE was his grudge with the Georgia territory. Piper was fired and blackballed from the territory. The firing was because of him turning up late for a match. Once in WWE, Piper proved to be a crucial figure for the company in ending the whole territory system. The territory that blackballed him eventually died out due to the company he worked for.
Paul Heyman
WCW has pissed off a lot of people during their tenure. Paul Heyman is the second worst name in that list. Heyman had a memorable run with the Dangerous Alliance back in WCW before Bill Watts fired Heyman. The reason for the firing was falsifying expense reports, but the claims were not proven.
An angry Heyman soon joined ECW and became hell bound in running WCW out of business. He was not able to do the same with ECW, but he helped WWE in doing so. WWE took up the Attitude Era style of ECW and won the Monday Night Wars. And Heyman, he went on to become one of the legendary managers of his time.