raiden is op because he has 586340 hit confirms lololol
In all seriousness, I hate hit-confirms a lot, but they're all Raiden had going for him. Also, with the removal of his grab into super, none of his are as safe or spammable as Fat Princess's, Evil Cole's, etc. He's still very strong, but not extremely overpowered as some people like to say now.
Now, Drake, on the other hand...but that's a different topic.
This is quite possibly the worst user on GameFAQs: http://www.gamefaqs.com/boards/user.php?=2426382