Frostwind Virago
Medium fey, neutral evil
Armor Class 17 (natural armor)
Hit Points 237 (25d8 + 125)
Speed 30 ft., fly 60 ft. (hover), swim 20 ft.
Saving Throws Dex +11, Wis +8, Cha +10
Damage Immunities cold
Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks
Senses passive Perception 13
Languages Auran, Common, Elven, Sylvan
Challenge 16 (15000 XP)
Captivating Call. While speaking, the frostwind virago can force each creature within 300 feet of it to succeed on a DC 18 Wisdom saving throw or be charmed by the frostwind virago for as long as it remains speaking. A charmed creature can only take the Dodge action, and uses its movement on each of its turns to move its full speed toward the frostwind virago. The creature can repeat the saving throw if it takes damage, ending the effect for itself on a success. A creature that succeeds on its save is immune to the Captivating Call of all frostwind viragos for 24 hours. Frostwind viragos can’t be affected by each others’ Captivating Call.
Legendary Resistance (1/Day). If the frostwind virago fails a saving throw, it can choose to succeed instead.
Magic Resistance. The frostwind virago has advantage on saving throws against spells and other magical effects.
Mind Freeze Aura. Whenever a creature starts its turn within 30 feet of the frostwind virago, that creature must succeed on a DC 18 Wisdom saving throw or have disadvantage on attack rolls and ability checks until the start of its next turn. A creature that fails its save by 5 or more is stunned until the start of its next turn instead. A creature that succeeds on its save is immune to the Mind Freeze Aura of all frostwind viragos for 24 hours.
Actions
Multiattack. The frostwind virago uses Icy Vortex if it is able to. It then makes two attacks.
Frostbite Touch. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 24 (7d6) cold damage.
Icy Vortex (Recharge 5-6). Each creature within 30 feet of the frostwind virago must make a DC 18 Dexterity saving throw, taking 28 (8d6) cold and 28 (8d6) piercing damage on a failed save, or half as much damage on a success.

These fey are the embodiment of the dispassionate cruelty of winter, and the fury of a raging blizzard. They usually live alone, but sometimes use frost giants as servants. They live in the remotest tundra, consuming mammoth meat and the like, getting water from the snow and ice. They are thoroughly malevolent, and despise warm-blooded creatures. They like to torment them before killing them, or lure them into particularly cruel traps. Despite this, they can be reasoned with, and sometimes will work with other creatures toward some common goal. Some powerful frost giant lords have a frostwind virago as an advisor or agent. A typical frostwind virago stands around 5 feet tall and weighs around 90 pounds.