10 Best One-Off Characters In The Marvel Cinematic Universe
3. Dr. Ho Yinsen
It is no exaggeration to say that without Yinsen there would be no MCU. In his brief time on screen, Yinsen not only saves Tony Stark's life but allows him to become Iron Man.
Tony and Yinsen meet when terrorists capture them and force the pair to develop weapons for them. Instead, Tony and Yinsen create the first ever Iron Man suit, giving them a chance for escape. Unfortunately, Yinsen is killed in the escape attempt, but as he sees it, he can reunite with his family in death. Shaun Toub does a great job in the role, and makes the death scene especially emotional.
Yinsen doesn't just help Tony create the Iron Man suit, he helps create Iron Man. Before the cave, Tony was too selfish to ever be a hero. Yinsen's dying words to Tony are "Don't waste your life." The story of the Infinity Saga is the story of Tony not wasting his life, and that's all because of Yinsen.
Though Yinsen pops up for a quick cameo in Iron Man 3, it wasn't a continuation of his story, so he is a one-off character. Despite being just a one-off character, MCU fans owe him everything.