Speculation:Nightslayer

From the Lyorn Records of the Dragaeran Empire

Given that Nightslayer's true Serioli name actually translates to "Loci for different levels of energy from various planes of existence", it seems quite likely that this weapon has powerful Necromantic powers.

This may include the ability to revivify persons, or even open Necromantic Gates. Likely, The Necromancer has been (or will be) involved with Telnan's training at some point.

Nightslayer may possibly be the most powerful of the Great Weapons so far revealed. At the least, its psychic presence is described by Vlad as being even more predatory, vicious, and powerful than that of Blackwand, the high-water mark of Great Weapons to date.