Synopsis / Summary / Plot
The Avengers have defeated the Ashen Combine, the 1st Tribulation Event predicted by Kang The Conqueror, and the villains' sentient orbiting Impossible City has agreed to be their new base.
But now we seem to be in the middle (or rather near the end) of another crisis. The Moon is split in 2 and things are raining down on Earth. We see large alien beings stomping around while humans vomit blood(?). The Avengers, especially Scarlet Witch, are mourning a fallen Vision. It's the same gang as current but they are wearing older costumes, especially Carol Danvers dressed as Warbird or Ms Marvel. However Captain America is still Sam Wilson.
We learn that the Black Presbyter is unravelling reality and the children of the Anti-All have been released. The multiverse of the 8th Cosmos is dying and the Avengers can only avenge it. But 1 by 1 they are defeated:- Thor then Carol then Black Panther (invoking the Tiger God who also dies) and Iron Man then Cap boosted by the power of Wanda Maximoff.
The Witch is left alone but then she realises that someone has been describing events in a voiceover to us. She sees someone watching who turns out to be Nightmare. He agrees when she calls it all a trick but says it's also real. As he defends himself from her attack she wakes up to find the others asleep on a floor in the Impossible City. (And they're all in their current costumes including herself.) They're all there except Vision. (Well, I don't see Panther either, which may or may not be significant.)
Then Vision enters and says that he saw them all fall asleep, but then some others arrived. They now follow him in and announce themselves as Myrddin and his Twilight Court who are here to put an end to Kang.