"Stay well away from that sword, it has the habit of killing more than its master chooses."
About
Stormbringer and Mournblade are brother blades. To the casual view they are assumed to be common Valyrian steel but with further inspection that assumption is thrown into doubt. The two swords are inherently superior to common steel or other metals like Valyrian steel is, but their sharpness seems to go even beyond that. The most obvious signs, however, are all related to how they are obviously and unsettling, deeply ensorcelled. Who did this work — Elrys, some long dead Valyrian or another source — is unclear. Some theorize that they come from some other culture of terrible sorcerous knowledge as they are so similar to Valyrian steel but also so different.
Stormbringer is a huge, finely wrought great sword, with a blade at least five feet long from the hilt. The hilt itself is embedded with a large spherical ruby that makes one think of an eye for it seems to be alive with life and awareness. Or so some claim. Unlike Valyrian steel, which is a deep grey in color, the blade is pitch black and etched with runes that seem to have little to do with any known variation of Valyrian. At times, the runes glow and change color, cycling from red and purple to blue. Its brother Mournblade is much the same in appearance.
There are times when in battle the blade is engulfed by black light and dark fire. Legend says that it even screams, as if it were not just a sword but a living thing. Any being slain with Stormbringer will have his or her life force leeched out of them, into the sword and then into its wielder — this is what has helped keep Elrys alive and vital. There are whispered fears that it can drink the soul from any unprotected living creature upon delivering any wound, even a scratch and that it takes what it wants. That the blade, like a dragon, is something terrible over which there is only the shadow of control.
For a time Mournblade was wielded by Elrys’ Cousin Yyrkoon until he was killed by Elrys in battle. Since then, it had remained in the Dragon Palace in Asshai under close guard and none have used it since.
Stormbringer however is kept in storage under guard only until Elrys is reborn and is old enough to claim it. To touch Stormbringer or Mournblade without permission or authorization is an immediate death sentence in Mōriblēnun and to attempt to wield one means a death sentence of unimaginable horror and cruelty. It is said that, despite relying so heavily on the sword to maintain his health Elrys Doom-bound loathed the sword but was helpless without it because of the strength and vitality it transferred to him. This relationship has continued on with every Elrys to come after Doom-Bound as they all rely on the sword for strength and loath it for the evil it seems to delight in doing in their lives.