John Freeman in Half-Life: Full Life Consequences, particularly as a result of the Djy's machinima adaptation of Free Man, which shows him pile driving a train, among other feats. In the climax of Free Man, he keeps killing Combines despite being shot with rockets and stabbed, (using his "bear hands" because bullets aren't fast enough).
In Stray, Big Boss is a Memetic Badass to the rest of FOXHOUND. Of course, he is a formidable warrior, but the rumors about his missing eye alone get into mythic territory.
According to Wolf, it had been given as down payment to a demon in exchange for invincibility in battle, and the day it came back for the other was the day he would die.
Nobody Dies makes Shinji Ikari one in-universe after being the only one left concious after a Bar Brawl. ...It's a long story.
Specifically, a Bar Brawl at a UN banquet, where the two main combatants were Gendo Ikari and the President of the United States... Who in this fanfic is Stephen Colbert.