Scott Summers/Cyclops
Scott Summers possesses the ability to fire red beams of concussive force through his eyes, destroying anything around him. His body absorbs energy from the Sun and fuels it into the energy beams stored within his eyes, and he is hence immune to his own power. Due to his inability to switch off the beams, Scott was brought to the X-Mansion by his older brother Alex, where Professor X took him in and helped design a pair of specialized ruby quartz glasses to help block the beams and safely diffuse them. Cyclops was later chosen to succeed his mentor and became the X-Men's field leader.
Jean Grey
With her advanced telepathic and telekinetic abilities, Jean Grey has the potential to be even more powerful than Professor X. With her telekinesis, Jean can move or immobilize objects with her mind, and also create Telekinetic shields and powerful blasts. With her telepathic powers, jean is able to read minds, communicate mentally and project thoughts. Jean is also in possession of the mythical Phoenix Force, which enables her to generate fire and disintegrate matter on a molecular level, and also amplifies her psionic abilities to near-unlimited levels.
Kurt Wagner/Nightcrawler
Kurt Wagner is a mutant with a physical appearance of a demon, which made him an outcast well before his mutant powers fully manifested. He has the ability to teleport short distances, grab objects with his prehensile tail, and also camouflage into shadows.