Carefully He's a Hero - blood donor hero

Even just "hero" is an understatement here; this dude potentially helped erradicate a disease at its root and saved an entire portion of a generation of humans around him for as long as he lived his adult life. This is a legendary hero we are talking about here. He quite literally transcended his own basic human needs and lived for a greater cause, and never demanded any recognition for it. If not for the fact that this is actually documented to have happened, I would not believe such a person to even be real these days.

This is like the good end of Bioshock 1