The Marvel Cinematic Universe has changed the landscape of what franchises and films alike can do with a shared, cohesive continuity that ties everything together. Throughout the years, the MCU has made efforts to show their Universe is "All Connected" through throwaway lines to casual viewers or what have you that leads into the film (or films) that will eventually come out years later: (see Senator Stern showing up in The Winter Solider and the "Stephen Strange" reference).
So how does this lead us to the biggest references and teases for the two-part bohemoth that is Avengers: Infinity War Parts 1 & 2? It's fairly simple (or complicated) Let's start with the cloud over the MCU.
The almighty quest for the Six Singularities. The "Infinity Stones" have been the throughline throughout the Marvel Cinematic Universe, connecting each film and ultimately uniting the Avengers against intergalactic threats and pouty A.I. Thanos has his sights on the Stones and even has had the Chitauri Scepter (Mind Stone) in his possession and the race of said beings who likely crafted the Scepter for Thanos (OR one of the Four Cosmic Entities who forged the stones, more on them later).
His quest for the stones themselves are not for the power, the destruction of the universe, or what have you, what makes Thanos different is his one identifiable human trait, love. It makes him extremely unique and it makes for one exciting experience when we finally see him on the big screen. His love for his adopted (stolen?) Children, and his ultimate courtship.. Death.
Although we haven't seen much of Death (only in picture form) thus far, we can see how this cosmic entity will be something incredible to see on screen. The very idea of Thanos collecting the Stones (and challenging the Avengers) to court Death herself is what makes this iteration, and as the comics, an incredible thing to behold. The idea that Death and the other Cosmic Entities (Eternity, Infinity, and Entropy) were the ones to forge the stones is also a very interest twist on the lore of the stones themselves.
I believe this is something fans in the MCU have seemed to overlook in the grand scheme of why Thanos is collecting the stones in the first place.
Josh Brolin, the voice and movement behind Thanos put it perfectly when speaking on Death, and Thanos' motivations in the MCU:
"His relationship with Death, who is actually the woman, I love that. You can take Sin City (in which Brolin plays a man obsessed with a dark-hearted woman) and pump it full of steroids, and then you have Thanos. I like that he’s motivated by that, not just motivated by destruction or death or this or that. He’s motivated by a very identifiable, human trait.”
Also, for those who have not seen the mid-credits scene from The Avengers, here is a refresher:
Well, thats all from me for now on this. Thanks for reading!