Dark Phoenix can make regular and sometimes even hyper counter moves worthless, because she shoots tiny fireballs with her attacks. The fireballs hit first, so it will knock you out of your counter move before she hits you with her physical attack. Fortunately, though, you can take advantage of this by using a projectile counter instead. Because you don't have to worry about high and low with the projectile counter, this actually makes countering easier. Just time your projectile counter with her attack, then cancel the counter into a hyper, DHC into another one, and that should finish her off. This only works with Wesker and Taskmaster, though, because Amaterasu's projectile counter doesn't have an attack. Magneto's just works like it normally does, because the Force Field will absorb the fireball before the physical attack hits.