He was officially KIA. You were informed of it after the mission was complete, but he wasn't truly dead. He was a ghost and he was following you everywhere.

You went to your classes feeling nothing but his cold spirit following you. He rolled some pencils across your desk to try and get your attention but it failed. Some at night you'd swore you saw his apparition standing over your bed. He kept messing with your phone changing the songs that were playing to get your attention.