I searched at sage cats/book ghosts for 4h and found multiples of all other weapons that drop there except Maple Demon Axe. A guildie also searched at dark drakes and found nothing. I have never seen this item anywhere in the FM. I know it was coded for but can GM confirm that it drops at all?
Oh, that's weird cause another guildie went to the maple weapons coding page and checked the ID of monsters that dropped demon axes, which turned out to be book ghost, sage cat, jr lucida and dark drake. Do you remember what you got it from?