9. His Father Created The Avenger, Wonder Man
After Captain America was unfrozen and joined the Avengers, Heinrich Zemo banded together a group of supervillains to oppose them called The Masters of Evil. When he learned of a disgruntled ex-worker of Tony Stark called Simon Williams, Zemo believed he could use him as an inside man to infiltrate the Avengers' base.
Blasting him with an ionic ray, the Nazi supervillain transformed Williams into an ion-controlling superbeing called Wonder Man. To ensure Wonder Man didn't go back on his word, Zemo altered his metabolism so he would die within a week unless he received an antidote.
However, Wonder Man refused to be used as a tool and instead, warned the Avengers of Zemo's plot. Although Zemo was defeated, Wonder Man died after he failed to receive the antidote.
With the help of Vision's technology, Williams was revived as a being composed of ionic energy. Wonder Man has proven to be one of the most powerful and resourceful Avengers in recent years and it's all ironically thanks to Heinrich Zemo.
The masked menace never got the chance to see Wonder Man blossom into one of the world's greatest heroes, since he died shortly after.