I think that successful rushing involves 2 things: a) getting in and opening up room for pressure and b) maintaining that pressure.
The first is done by magneto’s mobility. 8 way dash, 2nd fastest wave dash in the game, tri jumps etc all give him an edge over other characters in terms of the ability to get in and stay close to the opponent. Tri jumps with hp and hk are great for applying the pressure, and tri jump lk and even lp works well in confusing your opponent. Add those to an assist like Psy and you’ve got a a character that can go high to low, switch sides and mix up in miliseconds. The best thing is that you can go from defense to offense in a split second, and in so many ways too. From sj hp addb hp/hk (mag’s main way of building meter), you can either dash in tri jump, dash in c.lk + assist or heck dash in, jump airdash over + psy. It’s damn flexible. Use mag’s mobility to get in and stay close.
Now how do we keep on the pressure? Mix up and Reset. A few Basic resets off the cuff:
Rom, dash under c.lk + psy
Rom, dash under tj lk c.lk
Rom, sj lk addf (switch sides) addf lk
c.lk c.lk + psy, c.lk c.hk hyper grav, c.hp sj airdash down dash under into whatever
throw resets, etc.
That’s what seperate average magnetos from the great ones. Keep your opponent guessing, use FS set ups like the 5 fierce, sj hk addf lk hk and stuff like that. And I really like what tech said about how opponents only have a 25% chance of blocking Magneto at every opportunity. If you are able to keep your opponents in such situations, then I think your rush will improve by leaps and bounds.
The subtleties of rushing differ from character to character of course. For instance with the big 4 you don’t wanna blind dash in on to Storm or Cable because of their s.hk. You don’t wanna airdash straight against Sentinel, coz that’s pan ( j/ sj hp) territory, etc.
You’ve gotta be careful rushing as well. Although it may sound like an oxymoron, too many magnetos die coz they blindly rush. Watch out for stuff like the above, as well as assists like Commando or Cyke. Try something like rush, block/see the reaction of your opp, rush again. More often than not, you can beat amateur opponents who like to mash on assists by blocking the AA, tri jump/ airdash over the other side, c.lk + psy or c.lk c.mp and double snap for the win. haha.
hope that helps. just my 2 cents