Wasn't there an ask chain about sin-powered IK? I would humbly request your thoughts on combining that and the newspaper sins ask (the part where you gave them their own custom sin if you would) please?
ooh okay let's see... i'm not sure how i'd translate their sins to powers so let's do some spitballing. i'm guessing the avatar-of-sin system is what gives the brothers their Special Powers, while the club are all regular demons*, so they don't really have special sin power-ups
pacts with demons allow you access to their powers because it's a connection at the soul level.... the club doesn't have pacts with ik, but since they do share a connection at the personal level, maybe their version is based in their knowledge/history instead?
in this case the power-up would be like a sort of proto-pact, where the demon is letting the human briefly borrow some of their power in a moment of extreme stress. though i'm not sure what the powers would grant?
i'm thinking instead of powers it 'grants' certain attributes. for example alecto (disregard of consequence) grants tenacity and durability/recklessness, wiz (blasphemy against nature) grants wisdom/'forbidden knowledge', astaroth (apathy) grants rationality/detachment
mephisto is an unusual case so i'm still not sure about him... if this was a game his power-up would be simply named "something mysterious", and you don't know which stats he's boosting but you do feel stronger...
(* mephisto is, by most metrics, an ordinary demon now - he does technically still have the differing chronodae biology, but doesn't have the powers anymore. in extreme situations he can access its remains, but that requires a specific medium to channel it through (e.g. a sorcerer, like solomon does during the king arc in jtta; solomon also used to have a pact with him))









