UPDATED VERSION AGAIN
Based on/combining elements of Shattered Angels, Noragami, Seraph of the End & a few other sources
Premise
Peace certainly was a rare and beautiful thing, wasn't it? Hard to find, but when you could, it would fill you with relief and comfort. A sense of being able to relax. However, peace isn't the best thing, in truth - for with such good feelings, anticipation and fear can sneak in as well.
Rightfully so, in the case of what is now to occur.
See, you sorry little folk were in that state before all of this, weren't you? Before His Lordship summoned you here? Of course, clearly his little attempt greatly malfunctioned, as you worms didn't end up where intended. Difficult creatures, aren't you? No matter - His Lordship shall harness what he needs from you soon enough. Even the Absolute Angels and their puny outsider allies cannot save you now.
--
Right when things seemed to be getting normal, or perhaps not, it all came crashing down. Oh, well- there's no use complaining, because it won't change that you've been brought into a Murder Game. There's a small chance of you getting out alive, but we'll get to that later. For now, let me just get this out of the way.
Welcome to the Murder Games.
It's highly likely that you won't make it out of here alive, but feel free to hope, if you like. There are murderers out to get ya, you'll have our least favorite psychopath sending his minions out to get you, and much more. There's a lot of ways you can die, to put it simply. You've got guys on your side, too, though. Guardians of sorts, investigators that'll help you unravel just who's doing the killing and dirty work for the big man, and, well, the lot of you that are innocent. Regardless of who you are, of what you can or cannot do, you can't change that you've been brought here. There's no choice but to do what you must to survive, if you have a desire to see the light of your world's day again.
...Oh, and one last thing; be careful. Almost everything you do will have an impact; And you don't want to get on anyone's bad side here. This isn't some kiddy park, and murder is no game.
Roles
Roles for this game will be as follows:
Absolute Assassins - As the name implies, these will be the people that commit the kills. There will be 3-4 Absolute Assassins.
Absolute Innocents - These characters will be the normal players of the game, and there's no special perk for this.
Absolute Investigators - Each round, these people will be able to investigate a player. When they investigate someone, they will be told the role of that person - be they an Assassin, an innocent, a sword, etc. There will be 3 Absolute Investigators.
Swords - The characters with this role will be something akin to a bodyguard. They will pick *one* character to be the guardian of, and when an assassin targets a character that one of the swords is a guardian of, the sword will die in place of the character that they're guarding. In addition, swords will gain mana slightly faster than other players. There will be 4 swords.
Absolute Extractor - Characters with this role will be capable of draining other players of Mana. Every other round, the extractors will be allowed to steal a bit of Mana from another player, thus earning the Extractor more Mana, and in turn more power. The greatest amount of Mana that will be possible to steal at a time will be 12. The identities of the Extractors will be hinted at through how much power they have, so you'll want to keep an eye on how much Mana/power people have. There will be 3 of these.
Abilities
In this game, characters' powers will be nerfed - but not in a typical sense. They will all function on Mana, and with the more mana they have, the more of their original abilities will be able to be used. The less Mana they have, in turn, the less powers they'll have. Every character will start off with the same amount of Mana(that will be fairly little), and will be able to gain or lose it from certain tasks they do. They can also have Mana stolen by the Extractors. Even humans and the like can earn power this way.
The Afterlife
When one dies in this game, they will be reincarnated as a younger version of themselves in a different area from the main group. With each activity- or 'quest' -they complete, their aging will accelerate and they will regain a bit of their abilities, bit by bit. Eventually, they will be reunited with the main group.