Déjà

Déjà was an AI who trained the Spartans in their first stages of training at the CASTLE Base and Reach Naval Academy facilities on Reach. Her educational lessons were part of the Spartan's training program, meant to increase their strategic thinking. She also educated them in history, math, and other things most people are taught.

Her counterpart, Chief Petty Officer Mendez gave the Spartans rigorous physical training to make them into soldiers. This, along with Dr. Catherine Halsey's physical augmentations and MJOLNIR armor, made the Spartans intelligent, strong, and fast.