All-Black the Necrosword

All-Black the Necrosword is an ancient weapon. It was forged at the dawn of time as a blade to be turned against gods, and it has passed through many hands across the ages since.

The weapon takes shape out of living shadow, flowing from its bearer's hand into a sword, a spear, or whatever form the moment asks for, and knitting itself back together when it is broken apart. It calls out to anyone close enough to hear it, asking to be picked up. In the hand it lends strength and speed past anything mortal, opens passage from one shadow to another across great distances, and draws shadow monsters out of the dark to fight alongside its owner.