Complex sentence: At the Royal Rumble, Brock Lesnar retained his WWE World Heavyweight Championship against John Cena and Mr. Money in the Bank Seth Rollins in a triple threat match, while Roman Reigns won the 2015 Royal Rumble match to face Lesnar for the title at WrestleMania.
Split into simpler sentences: At the Royal Rumble, Brock Lesnar successfully defended his WWE World Heavyweight Championship against John Cena and Mr. Money in the Bank Seth Rollins in a triple threat match. Meanwhile, Roman Reigns won the 2015 Royal Rumble match to face Lesnar for the title at WrestleMania.