it becomes darker and more heart-wrenching as it delves into the poignant pasts of both the MC and ML, revealing exactly what happened to them that led to their initial circumstances at the start of the story.

The ML's love for the MC is really deep, and he's only gentle and protective towards the MC. Even though the MC doesn't remember anything about him from the start, his feelings for the MC are still there. In the beginning, the MC is really timid and easily scared to tears (though as the story progresses, you'll come to understand that he's actually crying because of other reasons), but there'll be a twist in the latter half of the story. To sum it up, both MC and ML are really lovable characters whom I can't help but wanna hug after knowing what they have gone through. I just feel that it's a bit regretful that the portrayal of the MC and ML's relationship doesn't make up a large part of the story. So, this novel may not cater to those seeking solely sweet moments between them.

MC and ML did end up together forever so it's HE? But they will be forever stuck in that place.

Basically it's a world after death for sinners. The sinners will experienced death related to their sin.

There's another group of people other than sinners, "Nightmares" who carried out the punishment. Nightmares are people with "original sin"--that is--refusing to reincarnate. MC, ML, and a few others were Nightmares. They were given a role to protect the sinners so the malevolents won't kill them (if malevolents kill the sinners, the sinners won't die and will restart the cycle), if MC and co failed? They will be punished. This punishment is very unfair, for example: one guy was seen killing the malevolents by the sinner and he was punished to be imprisoned and eaten away countless times by malevolents for a day (no idea why this is punishable, as in the story ML was seen killing the malevolents countless times with no repercussion). The sinners only supposed to die once, while the "Nightmares" died countless times in painful ways.

The MC was amnesiac cause he's in the middle of punishment. His fault: He didn't protect the sinners. He stood by and watch the perpetrators who killed him get mu*dered by malevolents.

Also one of the Nightmare chose not to enter the cycle of reincarnation as self-punishment. They were filled with self-blame and guilt, even though based on the flashback, they weren't actually guilty at all.

You would think this kind of story would be a feel-good karma story, where villains received their just desserts. But no, it's a story about good people suffer in live and continue to suffer in death.