Alexander Summers, also known as "Havok", is a Mutant who once led the Brotherhood of Mutants and X-Factor. He is a sibling of Scott and Gabriel Summers, and a son of Corsair. After the Terrigen Bomb, Alex joined his elder brother's X-Army as a high-ranking lieutenant and member of X-Force—Scott's inner circle and SpecOps team. He fought alongside Cyclops during the bloody and catastrophic Terrigen War.