Major Kaidan Alenko is a human biotic and an officer in the Systems Alliance. He served as staff lieutenant under Commander Shepard on the SSV Normandy during the Battle of the Citadel and now heads the Special Operations Biotics Division at the Alliance Warfare Center. An Alliance tribunal recently called on Alenko to testify about his experience with the Reapers.
Alenko suffers from severe headaches because of the early-model L2 biotic implants that he was given as a child. The L2 implants have since been discontinued due to the risk of crippling neurological damage.