In the Marvel universe Havok is Cyclops' younger brother. Havok's 'power' is the ability to gather and convert ambient energy and sunlight to plasma blasts which he emits through his arms
"A mutant-hating, gun-wielding, mind-controlling religious sect in the middle of Montana turned you into a priest. Sounds reasonable. But then, I hang around with people who read minds, have claws, teleport, control magnetic fields and shoot power beams out of their eyes... so I'm hardly grounded, now am I?"
- Havok, Uncanny X-Men #424