i found a bug with scorpion sadly, he should normally be even better with raiden. after raidens back throw, you should be able to juggle with scorpions up kameo, but he spawns on the wrong side of raiden, far off the screen. you only hear the fire and see the kameo bar go away.So. Some time has passed since release. What cameos have you been using?
For combos I think Scorpion is the best since you get ~30% no bar from any starter and ~45% one bar combos. Also has an overhead special which goes nicely with F434 and gets you decent damage for what it is (FYI it's a combo starter).
For pressure/chip damage I've been using Kano combining him with DB3. Also some zoning help is appreciated on Raiden.
Maybe we could get a separate thread for discussing Raiden cameos, @RoboCop ?