The very end is why I need to play again and fiddle around with different choices. I was playing this round as Tactful Good. Not overly flirty/blushing with anyone because death game in progress is not really the time for hookups; and all around nice to all, even those I think are sus so as not to prematurely tip them off. It *seemed* like it was going well. So the last sequence of events went by in a flash of curveballs blindsiding me and now I'm not as sure what to think on who the original third demonheart was.
As for the self confessor- the first game taught me never trust their type because they may be a conniving hunter waiting to pounce. So... if my conspiracy is wrong (and the theory admittedly is a stretch, but I don't want to admit that character is dead in such an abrupt off screen fashion), it's possible the confessor is the killer, and potentially working with an accomplice or two for mutual gain. But that expectation of "don't trust this obvious parallel to a character from the original game" can always be subverted and it's possible they've been the third all along. I'll have more theories when I've played through a few more times to absorb the general plot completely and see the variations on events.