Scroll of Blessed Shard

Location: SpellCraft
Price: N/A (Use Elemental Ink and make this combination)
Sellback: 25 Gold
Type: Item
Description: If your target is undead, this attack pierces your targets armor leaving them extremely vulnerable to all attacks for 10 seconds.
Notes:

• Stacks up to 99.
• Can only be used against Undead Monsters.
• Cooldown lasts 30 seconds.
• Deals 50% Spell Damage and applies Vulnerable to the target, increasing its All In by 50% for 10 seconds.
• Crafts in batches of 10.
• Used in the 'Shadowslayer Summoning Ritual' quest.

Thanks to Flitterifie.