Farbane

From Syra D&D Wiki

Farbane is a magical waraxe carved from a mysterious purple crystal. This material makes it exceptionally strong against aberrations, as well as providing its wielder some protection against the same. It is currently wielded by the half-orc ranger Harthur, who found it in the Tomb of Horrors.

During the Battle of Silverstone, when it was discovered that the store heart of a powerful aberrant monstrosity had been implanted into Boccob's chest, Harthur used Farbane to shatter it and give the former god a merciful death. A portion of their essence was drawn into Farbane, further empowering it.