Complex sentence: Afterwards, Shane announced himself as the special guest referee for the tag team match between the team of Owens and Zayn against the team of Orton and Nakamura and added another stipulation that if Owens and Zayn were to lose, they would be fired from WWE.
Split into simpler sentences: Afterwards, Shane announced himself as the special guest referee for the tag team match between the team of Owens and Zayn against the team of Orton and Nakamura. In addition, Shane added another stipulation on the match that if Owens and Zayn were to lose, they would be fired from WWE.