When watching "Sword Art Online: Alicization - War of Underworld", and Asuna waxes poetic over how great it is that her friends were willing to risk losing their avatars (which represent hours of work) to save the lives of AIs (basically, a newly minted sapient life form), and she effectively equates several hours of work with a human life, did you also feel like reaching through the monitor screen and punching her in the head?
If yes, this anime is for you.
Deca-dence is a reverse Isekai - it is the story of a post apocalyptic world, where the majority of surviving humans are cyborgs (basically human brains in a brightly colored CGI shell), except for a small population living in a mobile fortress called Deca-Dence. These 'true' humans don't know about the existence of the cyborgs or anything else. Their fortress is under contant attack by 'Gadoll' - giant monsters bent on its destruction (FYI, gadoll is Hebrew for 'big').
The reverse Isekai comes in from the fact that the cyborgs create and pilot human avatars in Deca-Dence to fight the monsters and score points. It's a hugely popular game.
Oh, did I mention that the monsters are created by the cyborgs to menace the human population, to create a storyline for the game.
This anime faces all the questions that all the anime like Sword Art blithely skate past without acknowledging. It doesn't really provide any answers, but that's ok - good SF should make the viewer think, not spoon feed them answers
