Mercenary Twinblades | Dark Souls 3 Wiki

Requirement	Parameter Bonus	Attack Values	Damage Reduction %	Auxiliary Effects	Others
Strength	Strength	Physical	Physical	Bleeding	Durability
Dexterity	Dexterity	Magic	Magic	Poison	Weight
Intelligence	Intelligence	Fire	Fire	Frost
Faith	Faith	Lightning	Lightning	Curse
		Dark	Dark
		Critical	Stability
		Spell Buff
		Range

Parameter Bonus: Strength, Dexterity,Magic, Fire, Lightning and Dark bonuses - The scaling multiplier applied to the [Attack: stat]. Scaling quality is from highest to lowest as follows: S/A/B/C/D/E.The higher the player's [Str, Dex, Mag, Fire, Light] stat, the higher the [Attack Bonus: Stat] is (found on the player status screen). The higher the scaling letter, the higher the percent multiplier applied to the [Attack: Stat].This resulting bonus damage is added to the base physical damage of the weapon and is shown in the equipment screen in blue numbers as a "+ X". 
Durability: The weapon's HP, when the durability hits 0, the effectiveness of its attacks become weakened to the point of almost uselessness. When an items durability is low, a message will come up saying "Weapon At Risk!" at this point the weapon does not perform at it's best.
Weight: How much the item weights when equipped. 
Stability: How well the player keeps stance after being hit
Attack Type: Defines what kind of swing set the weapon has: Regular(R), Thrust(T), Slash(Sl), Strike(St)