Explanation A: They'd been locked up so long that they were presumed dead
Explanation B: They're just skilled trainees that don't die immediately in the room they're introduced
Explanation C: Like the Bricklayer in DROD: RPG, they're just skilled adherents of the Slayer arts who are nonetheless not official Slayers
Explanation D: Once, long ago, these two Slayers managed to track down a Delver in a zonally-deallocated hold. Eventually they managed to corner and kill them, but they got some blood splatter on one of the well-polished statues. This severely annoyed 75th Statue Arranger, who decided to take petty revenge by contacting their friend 35th Census Taker and listing those two Slayers as dead.
Explanation E: Due to a clerical error there are five hundred Slayers who are all 177th Slayer.
Explanation F: I want to put more Slayers in canonical holds and there's nothing you can do to stop me.
Explanation G: ???
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