Question: who are class 5 mutants?
Answer: Jean Grey/Phoenix. Even without the Phoenix force she is extremely powerful. ... 
Professor X. Omega level telepath, not much explanation needed.
Legion. ... 
Franklin Richards. ... 
Scarlet witch. ... 
Wiccan. ... 
Rachel and Nate grey (earth-295 not 616) Both extremely powerful. ... 
Magneto.