After all we didn’t know about the leviathan or calus until we accepted his invitation so why make a weapon that refers to a character that when it was made knee nothing about? Perhaps calus told Benedict to tell banshee to build the bow to give to us and banshee having reseted 44 times forgot until today?
Banshee is a bit of a drinker. A drunk, you would say. Likes to get loaded up and let’s the creative juices flow. Designs really cool stuff. Forgets about it.