Agent Coulson

The death (and resurrection) of Agent Coulson is, in fact, the biggest retconning on this list. And, unlike the reveal of HYDRA being infiltrated in all organizations, this twist couldn’t have been worse.

Thus, when he died in Avengers, Coulson showcased his heroism. Furthermore, his death wasn’t futile, since it was used by the rest of the team as fuel against Loki and the Chitauri army. However, to everybody’s surprise, Coulson wasn’t dead.

Yes, they tried to explain it in Agents of S.H.I.E.L.D. However, the best explanation is that Marvel saw an opportunity for a series here and took it. The waters haven’t been made clearer, though, since Coulson is still dead in the big-screen MCU.

Which is yet another mind-bending fact – Tony Stark should have been the first to find out that his old friend isn’t dead.