He is the man SEAL Team10 brings in to defuse Fatman's bombs on Big Shell. Stillman is also responsible for training Fatman and feels responsible for what Fatman has become. He has walked with a fake limp for years saying that he lost his leg attempting to defuse a bomb in a church that killed dozens of innocents. He helps Raiden and Snake defuse the bombs around Big Shell, telling them to freeze the bombs. That won't get rid of the bombs forever but it should be long enough for the incident to pass. Stillman doesn't understand the placement of the bombs. To him it feels like something is off, none of the bombs are placed to cause damage. By the time he figures out what is really going on it is too late, Snake has defused the last bomb. This triggers another set of bombs set to destroy Big Shell. These bombs are different and are not detectable by the detectors Raiden and Snake have already. He reveals to them that his leg is fine and can go off after one of the bombs. He leaves the other bomb to Raiden. Stillman finds himself unable to defuse the bomb and is killed sacrificing himself, feeling that he has atoned for not being seriously injured or killed in the church bomb incident earlier in his life.