The design was submitted by a solarium tier pre-order backer, who was granted the ability to design a weapon to be included in the game.
The weapon's long description reads as follows: "A sword of extraordinary dark power, once used by a powerful soul."
It has a glowing orb in the handle that emits fiery particles while it's held.
The Soulseeker's attack is a simple melee slash which has a fire time of 1.33, a base DPS of 17.5 and a knockback power of 30 (strong knockback), producing a slash power of 23.275.
When upgraded at a Weapon Upgrade Anvil to tier 6, the melee slash's base DPS increases to 24.5, producing a new slash power of 32.585. Additionally, the Soulseeker's appearance changes to the one shown below.
Apart from the addition of a gold star to the name, no other changes occur as a result of the upgrade.