Original: Batista won the 2005 Royal Rumble, by last eliminating John Cena, earning the right to participate in the main event of WrestleMania 21 against the champion of his choice.
Simplified: Batista won the 2005 Royal Rumble, last eliminating John Cena, earning the right to participate in the main event of WrestleMania 21 against the World Champion of his choice.