It's quite common for psionic mutants to have more than one power, i.e. the classic telepathy/telekinetic combo. Sometimes they'll even have powers that have nothing to do with psionics like Emma having both telepathy and diamond skin or Monet being a flying brick with telepathy.
If you were to limit a psionic character to just one power, what would it be?
For me:
Emma Frost - Telepathy
Nate Grey - Telekinesis
Rachel Summers - Telekinesis
Jean Grey - Telepathy
Kwannon - Psionic weapon creation
Exodus - Teleportation
Monet - Telepathy