To be honest, 2,1 online (Which is where most Raiden's are fought) does not punish as well as it does offline. Frame data and gravity is so wonky (online) that it makes spin probably the best option. Because more often than not, attempting to counter attack with 2,1 is met with a block.
And to the point of matchups to worry about. Cage isn't particularly relevant anymore in regards to Kung Lao online.
Sonya, Reptile, and Kitana are the only present problems that need to be countered at this point, but even these characters have heavily exploitable flaws.