I forget if I’ve posted about this before but I think my best locked tomb theory that I have actually zero evidence for is that the tridentarii were originally triplets and ianthe ate one of them in the womb.
the circumstances of harrow’s birth support the logic that would explain why ianthe would be a necromancer but not coronabeth. also ianthe’s WHOLE thing is that like, she’s been eating people from the get-go. she’s the only person at canaan house who had it in her to ascend to lyctorhood willingly, and that’s bc she’s been eating her cav from the start. it comes naturally to her. I feel like it would track with her character, given all that.
most of all though, it’s because the tridentarii lean into their aesthetic like nobody’s business. tridentarii from the third house, the trident knife, three of them (counting babs) showing up to canaan, etc. if they were TRIPLETS too? my main argument here is that it would be sickeningly on-brand in a way only ianthe could do