#WHOMST is re-locking the tomb. is it anastasia's ghost

[nonasbirthday]

I still don't understand why Crux had to die for the tomb to be opened at the end of NTN. Wasn't the tomb already open? How could it have re-set to need John's blood again?

It sounds like Paul was somehow able to get some of Kiriona's blood despite her impenetrable skin ("Take all of it." "I don't need all of it - but I need to keep it wet..."). And that maybe they only needed "fresh thanergy" because Kiriona (and presumably her blood) is dead. Because Harrow didn't need to kill anybody the first time she went in, right?

But in HTN it's implied that Harrow entered the tomb multiple times and that it took her a while to dismantle the traps in each section. And she presumably didn't have Gideon's blood under her nails every time she went in (hard to say for sure, since the memory recounted to us has been edited to be Certified Griddle-Free). (And anyways, doesn't Pyrrha say in HTN that fresh blood is thalergenic, not thanergenic? So why would Gideon's blood being fresh meet the thanergy requirement?)

So I don't understand why the tomb wasn't just open for our little rescue crew to bust in, and if it had been re-locked, why Crux dying unlocked it. (Or how they got Gideon's blood, really, but for that one I'm willing to just accept the magic of "it happened offscreen.")