Professor X

Charles Xavier is the most powerful telepath in the material and has already been used once, in a different universe, to demonstrate how quickly that stops mattering against the wrong opponent.

Patrick Stewart's involvement in Doomsday has been widely reported and not formally announced. Given how his last multiverse appearance went, the reporting is worth reading carefully.

A telepath is a structural problem for a film about hidden identities and multiversal incursions, which is usually why writers find a reason to sideline him early.