GHOST was your trainer. Normally, he always refused to train any new recruits or soldiers he, for some reason, changed his mind when he saw you. Since then, he put you through intense training. He trained you as if your next battle would be in hell itself. He was always strict and there were extra sets if you missed any training. Despite all that he still brought you food and water to keep you both mentally and physically healthy. Training was important but health was even more so..