Avengers 4: 8 Major Plot Predictions
2. Iron Man Will Take Out Thanos
In Infinity War, Doctor Strange mentions that he's seen millions of different potential outcomes for the Avengers vs. Thanos showdown. Unfortunately, our heroes are only capable of winning one.
From here, it's assumed that everything Doctor Strange does is in service of that one winnable outcome: allowing Star-Lord to snap Thanos from Mantis' sleep-state; handing over the Time Stone to save Tony's life; and essentially dooming himself to vanish in a cloud of dust.
Focusing on that Time Stone/saving Tony moment, it's unclear which part of that decision is fuelling the winnable future (i.e. does this future need Tony to be alive, or does it just need Strange to have given Thanos the Time Stone? Or does it need both?).
But running with the notion that Tony needs to live for the Avengers to ultimately triumph, we can safely say that Iron Man will prove extremely valuable - possibly even indispensable - in Avengers 4.
And what could be so important that Strange would basically sacrifice half of the universe just to save one man's life? Iron Man striking the killer blow against Thanos.
This ultimate outcome would be fitting, almost poetic; Iron Man kick-started the MCU way back in 2008, and by killing Thanos, he'd be the one to bring ten years of build-up and storytelling to a thrilling close.