Since these are "echo" spirits... maybe a solution is they can be "absorded" by our characters. Basically... if our characters touch their echo... it vanishes. Our characters gain a clear understanding of what would have happened if they made a different choice.
so in case you haven't figured it out yet it's a trap.
the chains are real and the runes are real.
But the body is fake. A human was true polymorphed to look like Ravyn. But they were already dead.
once four people have entered the room the door will close sealing them in and an antimagic field will activate. the door will merge with the wall sealing them in. and the magic holding the polymorph spell will cease, rendering the body back to it's original rotting form. (a dead acolyte was used)
Callo's claws and angus' axe will be able to get through the door. but it will take time.
its more delaying tactics.
some of Ravyn's hair and blood were used to fool the scry and a Amulet of Proof against Detection and Location was put on Ravyn to keep anyone from finding the real her (it's also preventing M'Kael from finding her.)
Amulet of Proof against Detection and Location
Aura moderate abjuration; CL 8th Slot neck; Price 35,000 gp; Weight —
Description
This silver amulet protects the wearer from scrying and magical location just as a nondetectionspell does. If a divination spell is attempted against the wearer, the caster of the divination must succeed on a caster level check (1d20 + caster level) against a DC of 19 (as if the wearer had cast nondetectionon herself).