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

Death Throes. When Wrath dies, she explodes, and each creature within 100 feet of her must make a DC 20 Dexterity saving throw, taking 70 (20d6) fire damage on a failed save, or half as much damage on a successful one. The explosion ignites flammable objects in that area that aren't being worn or carried.

Insatiable Bloodlust. If Wrath has taken more than 40 points of damage since her last turn, each of her weapon attacks heal her for the damage dealt during this turn.

Magic Resistance. Wrath has advantage on saving throws against spells and other magical effects.

Recurring Retaliation. Any time Wrath is targeted by a magic missile spell, a line spell, or a spell that requires a ranged attack roll, roll a d6. On a 1 to 4, the effect continues as normal. On a 5 or 6,the caster is inflicted with the same effect that Wrath receives.

Relentless Retribution.  Wrath's spiteful hatred of all things is so intense that she pushes past what would be thought possible. She may take three reactions each round of combat.

Smiting Aura. At the start of each of Wrath's turns, each creature within 5 feet of her takes 10 (3d6) lightning damage. A creature that touches Wrath or hits her with a melee attack while within 5 feet of her takes 10 (3d6) lightning damage.

Multiattack. Wrath makes two attacks: one with each of her chain swords. 

Chain Sword of Malice. Melee Weapon Attack: +14 to hit, reach 30 ft., one target. Hit: 21 (3d8 + 8) slashing damage plus 13 (3d8) fire damage, and the target must succeed on a DC 24 Strength saving throw or be pulled up to 25 feet toward Wrath. If she scores a critical hit, she rolls damage dice three times, instead of twice.

Chain Sword of Revenge. Melee Weapon Attack: +14 to hit, reach 30 ft., one target. Hit: 21 (3d8 + 8) slashing damage plus 13 (3d8) cold damage, and the target must succeed on a DC 24 Strength saving throw or be pulled up to 25 feet toward Wrath. If she scores a critical hit, she rolls damage dice three times, instead of twice.

Vicious Reprisal. If Wrath is hit by a ranged attack or spell, she may make a perception check against the attacker's stealth. On a success,  she magically teleports, along with any equipment she is wearing or carrying, to an unoccupied space it can see that is within 30 ft. of the attacker. She then makes a single melee attack.

Wrath can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Wrath regains spent legendary actions at the start of her turn.

Attack with Chain Sword of Revenge. Wrath makes one attack.

Attack with Chain Sword of Malice. Wrath makes one attack.

Fly. Wrath flies up to her full speed.

Walk.  Wrath walks up to her full speed.

Second wind. Wrath channels her fury, healing for 2d20.