Frigid Blade is a weapon action granted by 
Allandra's Whelm.
Description
You add your Proficiency Bonus as 
Cold Damage.
When the attack hits, apply Frostibe. The creature takes 1d4Cold damage when making a weapon attack.
Properties
- Damage
1d8 (1~8) + Strength modifier 
Bludgeoning - + ProficiencyCold
- Details
Attack roll
Range: Normal weapon range
Recharge: Short rest
Condition: Frostbite
CON Save saving throw
- When taking Cold damage, takes an additional 1Cold damage per turn of Frostbite remaining.
How to learn
Granted by the weapons:
Allandra's Whelm (inaccessible)