My personal theory in regards to Yoru has been that all of the Weapon Devils are her children (which is why they showed up for 4 Horseman vs Pochita) but the part of her that was eaten was the part that represents Weapon Humans (which explains the weird partial erasure there) so she doesn't remember - there's a really fun dramatic irony to the idea that Yoru's children were actually on Earth all along while she was searching for Pochita and that she's spoken to them without even knowing it.