It appears that Thanos may have been wrong about Doctor Strange in Avengers: Infinity War. While battling on Titan, the immortal villain says, "you never once used your greatest weapon," while talking to Strange. The "greatest weapon" that Thanos is referring to is obviously the Time Stone. However, a new fan theory goes into a deep study that may have proven that the good Doctor did indeed use his "greatest weapon" against the Mad Titan. There are a lot of fan theories out surrounding Infinity War and Avengers 4, but this one, though obviously not proven, is pretty good.
Many Marvel Cinematic Universe fans let out a collective groan when Doctor Strange summoned the Time Stone and handed it over to Thanos towards the end of Infinity War. According to a new fan theory, that was part of the plan all along. The new theory states that the Time Stone that was given to the Mad Titan was actually taken from the future, a future where the Avengers won the battle, which explains why the Infinity Gauntlet was so heavily damaged after the snap. Reddit user lol-guru had this to say.
"I would postulate that the time stone can be sent through time all by itself, going forward or backward. How would you play keep away with the time stone? Easy. Send it forward in time to where Thanos can't get it! The problem is (as comic fans already know) Thanos is immortal, so he can wait it out. Dr. Strange conjuring forth the stone the same way as Loki did the tesseract is a gigantic misdirect! Loki is able to conceal the tesseract with his godlike powers of illusion and while Dr. Strange could certainly be capable of mimicking this easy trick, I don't think that's what's happening. The stone is glowing brilliantly because it's actually travelling back in time from the future! When Dr. Strange hid the time stone it wasn't through some trick of light or illusion like Loki but by sending it forward in time to be used later. Only to be sent back when the Avengers had finished using it."
This theory could very well explain why some of the Infinity War footage showed some misdirects, like Hulk running on Wakanda. It's possible, though pretty far-fetched, that this footage could actually be from Avengers 4. Since the Time Stone can travel back and forth through time, the theory states that the Time Stone will arrive back on Titan and into Tony Stark's hands. The rest of the theory reads.
"The time Stone can travel forward or backward in time, but not space. It will appear on Titan soon after the snap presenting itself to Tony. This is also why Tony needs to survive. If the snap is inevitable then he is the only one smart enough to a) figure out what is going on when the time stone presents itself on Titan and b) study the stone in order to unlock the quantum realm (the same way the mind stone in the scepter allowed him to create Ultron). This is why the Gauntlet breaks from the snap! It's using a time stone from a reality where the Avengers have already won and sent it back in time. The paradox of using a stone from a mutually exclusive reality breaks the gauntlet and helps advance Dr. Strange's plan even further because it cripples Thanos' ability to fight back when the Avengers start mounting their counter offensive."
If any of this Infinity War theory is true, it could explain how Ant-Man is able to escape the Quantum Realm. Maybe it's Tony Stark who finds him and they work together to use Hank Pym's technology mixed with Stark's to fight Thanos and reverse the effects of the snap. Again, this is only a fan theory, but it's fun to think about, especially since there's about a year to go before the Avengers 4 hits theaters.
Is the Time Stone as powerful as Thanos thinks it is? If so, it could be the "greatest weapon" that brings the Mad Titan down in the end. After all, Doctor Strange was able to go into the future and see the one shot out of millions that would allow for everything working out. Strange is putting his faith in Tony Stark, which is why he had to live. Head over to Reddit to read the rest of the Infinity War fan theory and decide for yourself.