When used with Dungeons Gear specifically, it became clear that many weapons from Dungeons Gear (eg fighter's bindings, corrupted beacon) that are meant to bypass invulnerability no longer function as intended. Seeing as the Cross Necklace from Artifacts, which has the same function as the Holy Locket, does work with these weapons, I assume this is due to how the Holy Locket itself functions and not the weapons.

Added in ff21709

Wait til the next release.