With the first Avengers: Infinity War trailer now unveiled, fans of the Marvel Cinematic Universe have finally seen Thanos' arrival on Earth, where he'll take out Avengers and wax poetic about his destiny and "restoring balance to the universe."
In short, the Mad Titan is every bit as threatening as promised since his cameo in 2012's The Avengers, made all the more scary by the shot of him wielding the Infinity Gauntlet with a pair of Infinity Stones embedded in it. It's no secret that each Stone individually packs the power to decimate worlds, but collectively, they can destroy and even rebuild the cosmos. Let's take a look at the two Stones he's in possession of.
The blue one is the Space Stone, which we's previously seen powering the Tesseract. The Stones were repurposed from the comics (where they were originally known as Infinity Gems), and this was the first one that appeared in the MCU, first in Captain America: The First Avenger as a weapon of mass destruction used by HYDRA, and then used by Loki in The Avengers. In this trailer, we actually see Loki holding it up, but we're not sure if he's offering it to Thanos (who previously employed the Asgardian to lead the Chitauri in an attack on Earth), or if he's perhaps using it against the Mad Titan's forces.
The latter is a possibility, given that Loki appeared to turn over a heroic leaf in Thor: Ragnarok and is now fighting alongside his brother Thor, and his Asgardian brethren. In Taika Waititi's film, we saw Loki looking at the Tesseract (which Thor recovered in The Avengers and stored in Odin's vault), so this confirms Loki did steal it before Surtur destroyed Asgard. It seems that Thanos comes for the Space Stone, ready to kill any and all Asgardians for it, as evidenced by a bloodied Thor possibly marooned in space and rescued by the Guardians of the Galaxy at the trailer's end.
In the comics, this Stone allows users to manipulate the space-time continuum as they see fit, enabling interstellar teleportation. But in the MCU, it's used as a source of energy that can power weapons or even large portals, as seen with the previously referenced Loki-led Chitauri invasion, which could even tie in to the portals Thanos and his forces use to invade Earth en masse.
As for other stone, its purple hue indicates it's the Power Stone, aka the Orb we first saw in James Gunn's Guardians of the Galaxy. Ronan was tasked with stealing it for Thanos, only to be foiled by Peter Quill's team, who decided it would be better protected by the Nova Corps. Ironically, Quill was the only one who could even partially handle and seemingly harness its power due to his bloodline (that of a Celestial, as Ego revealed in Guardians of the Galaxy Vol. 2.).
In the comics, the Stone is red and gives its users unlimited power and stamina, basically offering them godlike abilities, but in the MCU, the purple-hued gem's power is much more lethal, seen as a somewhat of a virus that disintegrates any living material it comes into contact with. Decimating the Nova Corps to retrieve it would surely strike intimidation into the hearts of any opposition. It would make sense for Thanos to go for the easier smash-and-grab job first, as the Space Stone is merely housed on a ship with the Asgardian refugees, powering him up to then go after the full arsenal of the Nova Corps.
With two Stones down and four more to go, one has to believe that the heroes are already up against the wall. As for the other Stones, well, the Mind Stone is in Vision's forehead -- it's worth noting that there's an ominous shot in the trailer of what seems to be Corvus Glaive's (the leader of Thanos' hit squad, the Black Order) staff attempting to extract it from the synthezoid Avenger.
The Reality Stone (or Aether) is presumably still with the Collector after the Asgardians sent it to him at the end of Malekith's failed assault in Thor: The Dark World. (Coincidentally leaked footage earlier this week had Thanos ambushing the Collector at his base for the Aether.) The Time Stone is in the Kamar-Taj library, as seen last seen in Doctor Strange when the hero used it to undo Kaecilius' destruction, and the Soul Stone... well, its whereabouts are still a mystery.
Some theories hint that it's housed in Wakanda, which could be revealed in next year's Black Panther, further explaining why Thanos' army is there squaring off against T'Challa, Captain America and his "Secret" Avengers. Either way, what's certain is that the moment the Avengers have dreaded is here: Thanos is assembling his Infinity Gauntlet, and it doesn't look good for any of the Galaxy's Mightiest Heroes.
Directed by Joe and Anthony Russo, Marvel’s Avengers: Infinity War stars Robert Downey Jr., Josh Brolin, Mark Ruffalo, Tom Hiddleston, Chris Evans, Chris Hemsworth, Jeremy Renner, Chris Pratt, Elizabeth Olsen, Sebastian Stan, Benedict Cumberbatch, Paul Bettany, Samuel L. Jackson, Cobie Smulders, Benedict Wong, Zoe Saldana, Karen Gillan, Vin Diesel, Dave Bautista, Pom Klementieff, Scarlett Johansson, Tom Holland and Anthony Mackie. The film opens May 4, 2018.