i agree, all the raiden mains i saw were weaksauce. I'll go out on a limb and say this, i haven't seen a better raiden then mine towards the end after my fundamentals grew to be really solid, and if he is a similar design in mk10 i will play him alongside the character i deem most broken.
most raidens i saw played without sense or reason, he is character built to runaway and punish the opponent for overexerting themselves in either the footsie game or pressure defensive game. He is designed to neutralize the opponents options so you can essentially attempt to force the opponent into taking an unnecessary risk as a product of you having the lifelead.
In order for this to appropriately happen your footsies have to be top notch, you can't let them jump, you have to whiff punish, and you have to effectively teleport out of small gapped situations, for example, counter-poking with teleport or in a pressure gap when you read they are going to do a string. Ex teleport is designed as a free escape so you can backup and create space, and whiff punish if they make a mistake (or as a punishment for them reading a teleport). Some people try to use it as a pressure starter when he isn't a pressure character at all. He's a pick and pop and annoy the opponent character. I love his design, and mark my words if i deem him with the proper tools to compete i will use him in mk10 and be better than every other raiden.