- When activated by a Dark Knight, each successful attack that lands (even for zero damage) will cause the user to lose 10% of his/her current HP and converts that amount directly into damage. This additional damage is added to the damage of the hit, not separately as with En-Spells.
- When activated by a character with Dark Knight Support Job, each successful attack that lands will cause the user to lose 10% of his/her current HP and converts half that amount directly into damage.
- The Enhances "Souleater" Effect, found on Chaos Burgeonet/(+1), Gloom Breastplate, or Sable Cuisses, adds an additional 2% to the effect, dealing 12% of the Dark Knight's current HP instead of 10%. This enhancement does not stack from multiple pieces.
- Quick testing shows that the Souleater bonus from an augmented Dweomer Scythe may stack ontop of the previous pieces. See discussion.
- The damage penalty of Souleater is not affected by Defense or VIT, Damage Taken+/-% such as Defending Ring(-10%) or Black Cuisses(+13%), the Red Mage spells Phalanx or Phalanx II, -% Physical Damage Taken gear such as Earth Staff/Darksteel armor, -% Magic Damage Taken gear such as Coral Scale Mail, nor is it affected by the Paladin ability Sentinel.
- The damage penalty of Souleater can be nullified by Stoneskin for an amount equal to the HP equivalent that the Stoneskin provides.
- Souleater is subject to physical damage modifiers, examples being open-mouthed Hpemde(+100% damage), and Slimes(-50% damage); additionally the modifiers for damage type (slashing, blunt, or piercing) based on the weapon used will affect the damage dealt by the ability--e.g., Skeletons take extra damage from Souleater when used with a Club.
- While active, this ability increases the user's accuracy by 25.
- HP converted into damage for a Weapon Skill is calculated for all hits using the same initial HP (i.e. A four hit weaponskill like Guillotine will inflict 40% of current HP and damage dealt, not each hit successively).
- Each merit into Muted Soul will decrease the amount of enmity from, exclusively, Souleater damage by a -enmity value of 10.
- When used in combination with Mana Wall the user will lose MP instead of HP.