With Raiden
Distance helps. Force him to use projectiles and teleports. You have to read him really well to do this. Accept that you are much slower than he is.
Low hat or hat toss - Teleport behind him and either try to punish or create space
KL Teleport - On reaction this is hard tough. If YOU force him to teleport, stay crouched and either D1~shocker/VB, naked superman or uppercut.
D1 combo
d1~VB, dash f2 shocker, b31~superman - 27%
d1~shocker, b312~superman - 25%
Teleporting right before the kick comes out helps. You have to time it so the kick doesn't come out on the side you teleport.
Dive kicks - If you have the right spacing you can superman on reaction. Don't do it all the time though, you want your opponent to guess what you are going to do. If you read it, try to dash forward and block if he is just trying to whiff it. Your teleport helps a lot too.
Understanding Raiden's teleport
This is where a lot of Raiden players go wrong. When I first started playing competitively late decemeber, this was my problem. In a short time my level of play has jump A LOT since then. Not bragging in anyway, the NoVA players tell me this.
Random teleports should only be used if your opponent does not know the match up.
What you want to do with your teleports
Time your teleports against his moves. This is a huge problem with a lot of Raiden players. If you end up making him respect your teleports and he starts to play more defensively, that should mean you have the life lead. Keep your distance and you should be good.
A good way to practice this is going in practice and pick characters with advancing specials. Put them to do wake up attacks then knocked them down. Using sweeps give you less time to react but its probably the best way. NJP then dash back, should give you enough space to react if the sweep distance is too hard.
There is no comeback factor at all, you need to be confident and control the match.
This is from my experiences, sorry if it might be a bit off.
Edit: For got to add this
If he is respecting your teleport and waiting for you to make a mistake, a well placed D4 could help. D4 is 15 frames so thats why I said well placed. On block its 0.
On hit its +15. If you d4~tele and the d4 connects, you pretty much get a free grab. You could pressure after this but since KL is a lot faster, a grab would be better.
This is where a lot of players will disagree with me about. They think its useless. I haven't posted much there. When I was trying to learn, I got ignored so I'm not going to waste my time.