Cassandra Nova..........Everyone else

Ok Cassandra Nova is one of if not the baddest Telepath around she humilliated both Chuck and Jean. And treated Emma like no more than a nuisance calling her, "a bush league psychic" so if three world class telepaths like Jean, Charles, and Emma are nothing to her who would she consider a peer.

Nate Grey, Onslaught, and Phoenix (though each outclass her tremendously)

She destroys Nate.

Not sure about Onslaught but say they'd be around the same...maybe edge to Nova against the first form of Onslaught.

Phoenix would beat her.

Phoenix was/is one of the most powerful entitys in the marvel universe