Staff of Loss is a Glintstone Staff in Elden Ring. The Staff of Loss scales primarily with Strength, Dexterity, and Intelligence and is a good Weapon for those looking to play an ambusher type of caster. 

Elden Ring Staff of Loss Notes & Tips

• Weapon Skill: This armament has no skill. If the armament in the other hand has a skill, that skill will be used instead.
• This weapon can be infused with Ashes of War
• Staff of Loss can be upgraded by using Smithing Stones
• Despite the description, this staff does not block the casting of non-Invisibility spells.
• Boosts attack power of Invisibility sorceries by 30%.
  
  • Invisibility sorceries include Night Shard and Night Comet. Also note that night sorceries are not dodged by NPC characters, making this an excellent staff to fight enemies that tend to dodge other ranged attacks
  • As of Patch 1.03.2, this 30% damage buff will be applied to appropriate spells regardless if it is the staff being used to cast. It only needs to be visibly equipped on the player character to apply.
  • Despite seeming like they belong in the category of Invisibility, the following sorceries do not have increased damage or duration according to testing: Ambush Shard, Night Maiden's Mist, and Eternal Darkness.
  • Despite being categorized as sorceries of invisibility internally, the following sorceries are unaffected because they do not deal damage: Unseen Blade and Unseen Form.
• With 80 INT, this staff has: 179 sorcery scaling at +0 // 339 sorcery scaling at +25
• At ~80 INT, this staff will outperform any staff in the game in terms of raw damage, so long as you limit yourself to only night sorceries (which is quite limiting).
• Using 2 staffs simultaneously will cause the 30% boost to stack multiplicatively, creating the highest boost that can be attained for a single magic school (Gravity sorceries can be boosted similarly, but lack the ability to upgrade the staff)
  • This can only be done in NG+ or by getting someone to drop the second staff for you, as only one can be obtained per playthrough
• This staff has the same handle as the Carian Glintblade Staff, though it's a different color, and lacks a glintstone (or perhaps, it is just invisible).
• Sell Value:  

   200 Runes

• NOTE: As of Patch 1.09, the scaling values of this weapon were changed. Please refer to the Upgrades Table of this weapon below.
• Other notes and player tips go here

Staff of Loss PvP Poise Damage Values in Elden Ring

Patch 1.10 adjusted PVP Poise Damage of all Weapons including some Spells and Incantations. Please take note that these adjustments are exclusive to PVP.