This mace becomes more powerful as it is coated in the blood of it's enemies, and seems to have the very fabric of it's atoms change to metals of various kinds.
Origins
Once a fairly normal mace, the corruption in the Archives transformed the mace into something's whose composition was not stable. More sinisterly it became cursed and thirsted for blood, and it would latch onto its user and change them into terrible versions of themselves that delighted in giving the mace what it desired.