here in alice almost everybody plays magneto but they use psylockes AAA assist so every time they try a rush down you have to block high and low at the same time and that is not ossible because psy’s assist hits high exactly the same time mags launcher hits so they get you no matter what and if i jump back he dashes behind me and one or the other gets me and i try to kill her when she comes out with cable with the ahvb but by the time i am hitting her he is already behind me WHAT THE HELL DO I DO!!!
you don’t have to block mags launcher or psy assist high or low specifically…
just snapback mag to get psy… and if u just keep hitting mag he wont be able to call her out 
try it 
What char are you using? My suggestion would be to to super jump a lot. Never let Mag and psy keep you grounded, because you seem to have trouble blocking. If you have someone with a fast super, you can anticipate them rushing you down and do the super right before they call psy. You wouldn’t believe how many times I’ve caught people by doing that. Most Mag players who rely on Mag/Psy is too one dimensional, all they want to do is OTG you and what not. It shouldn’t really be that much of a problem.
Basic’s right. Also, see if your chars can confuse your opponent into calling psy accidentally. For instance, if you have storm, fly around a little, and right before you approach the ground, do a lightning attack back up, making him call psy. He will figure it out after a time, but until then, you can punish psy for coming out, and as you all know, she doesn’t take damage that good as an assist.
psylocke does not hit high, remember that, look for magneto tri jumping, when his feet leave the ground block high when he comes back to the ground block low and call a aaa