Alex Summers is the younger brother of Scott Summers (Cyclops) and son of Corsair, leader of the Starjammers. He has the ability to absorb ambient cosmic energy and transform and release it as waves of energy that heat the air in their path enough to turn it into plasma. He, himself, is immune to the intense heat he creates, as well as the optic blasts of his brother. Cyclops, in turn, is also immune to Havok's powers.
