It seems that Neira (seraphim) burned Hosa, and she herself died from his protection, i.e., he was a Doppelganger (although maybe an OIM was protecting him, but does it kill a seraphim, because protection can be broken, who knows)... but at the end it also says about a killer flying upwards (maybe Hosa's soul)
As for Vish, he might have been killed by an Archon? there is no fire, no chains... and Pandora was probably protected by an OIM (if he didn't go to Hosa)
I think that here the clue might be the enumeration of antonyms, and I noticed something similar in Tieru's signature about Heaven and Hell, so I suspect him in this murder... but I don't quite understand what the harp has to do with it. I will probably vote against him or against Cash, who so diligently protected Neira... I'll think about it more.