Trivia: Spoilers! Red Skull makes his long-awaited return to the MCU after his appearance in Captain America: The First Avenger. We discover that he's been guarding the soul stone as punishment, of sorts. However he's played by Ross Marquand, not Hugo Weaving.
Trivia: Kenneth Branagh, director of the first Thor movie, has an audio cameo. He's the one voicing the distress call from the Asgardians which the Guardians of the Galaxy pick up.
Trivia: Spoiler! Whilst Groot is turning to dust after Thanos activates the complete Infinity Gauntlet, he says "I am Groot" to Rocket just before he dies. James Gunn, writer/director of the Guardians of the Galaxy movies, confirmed via Twitter that Groot was actually saying "Dad" to Rocket before dying. (02:13:45)
Trivia: On Knowhere, Thanos is questioning The Collector, played by Benicio Del Toro, for the location of the Reality Stone. He asks him "Where is the stone?" at one point. This is a reference to a heist scene from the movie Snatch, in which Benicio Del Toro is robbing a bank and asks "Where is the stone?" with the same line intonation. (00:48:45)
Trivia: When Tony Stark blows Ebony Maw out of an opened gap, you can hear the Wilhelm scream.
Trivia: There is a post credit scene where Nick Fury contacts Captain Marvel.
Trivia: (SPOILERS) As a result of the shocking twist ending where half of the peoples of the universe disintegrate into nothing, Reddit organized a huge campaign where they would ban half the subscribers of the subreddit /r/thanosdidnothingwrong to answer the question "Who would survive if this actually happened and who wouldn't?" Directors Joe and Anthony Russo also signed up for the campaign. At the end of the campaign, over 300,000 people had their accounts banned, including Joe Russo.
Trivia: Josh Brolin used co-star Benedict Cumberbatch's motion capture performance from The Hobbit: The Desolation of Smaug as inspiration for his own motion capture performance as Thanos.
Trivia: When Thanos arrives at Titan, he is greeted by Doctor Strange, who is sitting down and playing with some rubble in his hand. When Iron Man, Thor and Captain America first see Thanos after he destroys the Avengers compound in Avengers: Endgame, he is similarly sitting down and playing with rubble in his hand. This could mean that Doctor Strange was mimicking what Thanos would do in the one out of 14,000,605 possible futures that he saw in which the heroes would defeat Thanos.
Trivia: The look of Black Widow with the white hair is a reference to Yelena Belova, a spy in the comics and second modern-era character to use the name Black Widow. She first appeared in Inhumans #5 in March 1999.
Trivia: Because Robert Downey Jr. and Benedict Cumberbatch both previously portrayed Sherlock Holmes, the writers toyed with the idea of having one of them say "No shit, Sherlock" to the other, but nixed the idea, as they felt it was low-hanging fruit.
Trivia: In this and other Avenger films, Bruce Banner (Mark Ruffalo) is depicted as standing much shorter than Tony Stark (Robert Downey Jr). In reality, Ruffalo is only one inch shorter than Downey (who is 5'9" tall); but Bruce Banner is always portrayed as a diminutive character in contrast to his gigantic Hulk persona.
Answer: "Doctor Strange" demonstrates that the Infinity Stones are useful in the most dire of situations, when Strange used the Time Stone to prevent Dormammu from taking over the Earth. It's also possible that some of the stones are indestructible. Wanda is able to temporarily destroy the Mind Stone by using her own powers, but the Power Stone will destroy any being that doesn't possess the strength to wield it, and the Reality Stone is shown to have a will of its own and defended itself when it bonded with Jane Foster.
Phaneron ★
Also, in the comics, if the stones are destroyed they will simply be replaced by something else or even stones again. They represent the existence of the universe and cannot be destroyed for real. Always only temporarily.
lionhead