Avatar of Vengence

Relentless tracker:  The Avatar always knows where its marked foes are as long as they are on the same plane of existence.

Undying hunter: The Avatar of Vengeance once unleashed to hunt its marked prey cannot be killed when reduced to 0 hit points it will go unconscious and rise again at full strength in 2d10 + 10 hours. Until the marked are dead or the curse that brought it fourth is broken it will not stop.

Spellcasting. The Avatar of Vengeance has innate spellcasting Agility it uses Wisdom (Spell save DC 18) It can cast the below spells

1/day Planeshift (can only target itself)

2/day Tree stride

Recharge 5/6 Hold Monster DC 18

At will:  Cause Fear DC 18

Misty step,

Multiattack: 3 melee attacks per turn 2 Claw and 1 tail attack

Claw Attack: +14 to hit, reach 5 ft., 1 target. Hit: 23 (4d6 + 10) Slashing damage. 

Tail Attack: +10 to hit, range 10 ft., 1 target. Hit: 15 (1d10 + 10) Piercing damage.

Anguished visions: The creature is wracked with telepathic visions of the crime that marked them and the screams of previous victims of the Avatar of vengeance. Target must succeed on an Wisdom saving throw (DC 18) or take 4D6 physic damage half on a successful saving throw. On a Failed save under 10  the target is stunned by the physic assault 

Snatching lurch: As a reaction when Attacked  the Avatar of Vengeance can lurch forward into the attackers space to grapple them. The target creature must succeed on a contested Athletics check to escape or be grappled. In addition this reaction causes the attack to miss if the target fails the contested check.

Leaping dodge: Despite the creatures size it is exceptionally mobile able to jump 10 ft in any direction to avoid an incoming attack roll.