#1 Ended a WWE Superstar's career: Samoa Joe
For any wrestler, injuring another performer or ending their career is very heartbreaking. WWE usually deals with it by banning the move that caused the injury, but the damage has already been done.
Tyson Kidd's career came to end in 2015 after being in the receiving end of a botched Muscle Buster from Samoa Joe during a dark match on Monday Night RAW. Kidd suffered a spinal cord injury, an injury he revealed only 5% of people survive.
Since he couldn't compete in the ring any longer, WWE offered him a role as a producer. After injuring Tyson Kidd with the Muscle Buster, Joe stopped performing the move and started using the Coquina Clutch as his finisher instead.
Samoa Joe is also not active in the ring at the moment due to an injury he sustained earlier this year. He's currently serving as a commentator on WWE RAW. He did reveal that he's not done wrestling though, so we'll definitely see The Samoan Submission Machine in the ring once again.