He did have a shoulder injury that sidelined him for a period of several months and in that time he and Stacy Keibler got the time they had so long desired to finally be together as a couple.
It was her love for him that motivated to Randy to make his surprise reappearance on June 16, 2005 to instead of attacking Undertaker like he did in real-life, he attacked JBL instead and out of respect for Taker he helped the Deadman defeat JBL in the no disqualification match.
Randy got the chance on July 26, 2004 on RAW to challenge for the title but he had to win a 20-man battle royal to get the number-one contender ship.
Then for one long year it was literal hell on earth for RAW when Evolution dominated the entire roster with bullying tactics among other things.
Also during this time he developed a gimmick which became known as "The Legend Killer" which was a gimmick in which he acted in contempt of legends and sought to defeat them or "kill them" like how a dragon slayer would kill dragons like he would defeat legends.
The battle between these great athletes was intense and no clear winner was apparent at first but a winner would have to be determined some how.
Randy decided to not have his dad Cowboy Bob interfere for he wanted to defeat the Deadman in fair and honorable combat in the ring.
Also during this time another good friend of Randy's Dave Batista became World Heavyweight Champion and so Randy out of respect for his friend decided to challenge Dave to a match on the RAW after Wrestle Mania. Randy did not of course win the fight but he tried as hard as he could and Dave shook hands with him after the match.