A sword belonging to the Kythor, a developer of Sword Art Online: Burst. When equipped on Kythor's back, the hilt is long and spiked, making it appear like they're dual-wielded spears.
There is no way to obtain this weapon, as it is a developer sword exclusive to Kythor. According to Kythor himself, he doesn't like to be disturbed about the weapons in-game.
Kythor has stated that the Kythor's Soulrender and the Kythor's Shroud change their stat values when new content is released.Kythor has recently changed the look of his Soulrender's to the bottom picture on this wiki page.