9. Sharon Carter Killed Captain America
The superhero Civil War was raging until Captain America saw everyday people step up to defend Iron Man, and Steve realized that he had made the wrong decision and surrendered. Rogers was taken into S.H.I.E.L.D. custody and, on the courthouse steps, the Sentinel of Liberty was killed. But the killing blow didn’t come from a sniper. It came from someone he loved.
Sharon Carter was the niece of heroic WWII freedom fighter Margaret “Peggy” Carter who had fought alongside Captain America many times during the war. The elderly aunt would regale her impressionable young niece with stories of her exploits, and this was at least partially the reason for Sharon to join S.H.I.E.L.D. as Agent 13 and go on to have a distinguished career of her own. She worked alongside the revived Steve Rogers and the two began a relationship.
Agent 13 fell under the hypnotic control of Dr. Faustus, while he was posing as a S.H.I.E.L.D. psychiatrist, and the Red Skull, Faustus’ superior. They planted a post-hypnotic suggestion in Sharon to find and kill Captain America. On that day, it appeared to everyone present that the villain Crossbones had killed Steve with a sniper rifle. But as Sharon kneeled over Cap, she shot him with a second gun. This gun didn’t actually kill him but displaced him in time. With Sharon and the Avengers' help, he eventually returned.