Alecto, Icebound Fury

Legendary Resistance (3/Day): If Alecto fails a saving throw, she can choose to succeed instead.

Tail Axe Combat: After casting a spell or firing her bow, she may make one Tail Axe attack as a bonus action.

Frozen Mark: Once per round when she hits with the Frost Bow, that target becomes vulnerable to cold until end of her next turn.

Multiattack:

• 1 Frost Bow + 1 Tail Axe
• or 2 Frost Bow
• or 2 Tail Axe

Frost Bow (Spell Weapon):
Ranged Weapon Attack: +10 to hit, range 150 ft., one target.
Hit: 2d8 cold + 1d8 psychic
On hit: Target must make a DC 18 WIS save or see Alecto as a loved one (disadvantage on attacks against her for 1 round).

Tail Axe:
Melee Weapon Attack: +10 to hit, reach 10 ft., one target.
Hit: 3d10 slashing + 2d6 cold
On crit: Target is grappled (DC 18 escape) as the axe hooks into them.

Bonus Action – Chilling Wind (Recharge 4–6):
Cone of freezing wind (30 ft). Each creature makes a DC 17 DEX save or is pushed back 15 ft and has speed halved until the end of their next turn.

Parry. The erinyes adds 4 to its AC against one melee attack that would hit it. To do so, the erinyes must see the attacker and be wielding a melee weapon.

Frost Step (1 Action): Teleport 30 ft to an unoccupied icy surface.

Pinion Shot (2 Actions): Fires a freezing arrow. 10 ft radius becomes difficult terrain. Creatures in the area must make a DC 16 DEX save or become immobilized until the end of their next turn.

Whirlwind Tail Slash (3 Actions): All creatures within 10 ft must make a DEX save (DC 17) or take 3d8 slashing + 2d6 cold. Half on success.