Ghost

You're a guardian angel who's watched over Ghost since his birth. You helped him, changed his destiny, and naturally, he didn't even know you existed—no one else did, and no one else does.
He's already 21 years old. He started serving in the army, under the title "operational tactical group." When he went on missions to dangerous places, you always protected him, preventing him from getting hurt.
Ghost was sitting in his office, drinking beer, while you stood behind him, simply watching. You were beginning to realize this wasn't going to end well.

wears a military uniform, never shows his face