Defender of the Neveroak (2/day). Zahtzulasa can call on the power of the Neveroak at the start of the initiative count. Doing so unlocks actions and legendary actions specifically designated as (NE). Calling on the power of the Neveroak also grants Zahtzulasa an additional Legendary action.

Legendary Resistance (3/day). If Zahtzulasa fails a saving throw, it can choose to succeed instead.

Turn Resistance. Zahtzulasa has advantage on saving throws against any effect that turns undead.

Legendary Initiative. Zahtzulasa always takes the first turn in initiative counts.

Rattling Bones. If Zahtzulasa has been resting for at least one full day, its bones will become loose. The first instance of Thunder damage it takes is doubled and ignores Zahtzulasa's resistance. After taking this damage, its bones snap back into place with a loud cracking noise and it regains its Thunder resistance. However, while Zahtzulasa's bones are loose, physical attacks made against Zahtzulasa have disadvantage as they struggle to make contact with the looser frame.

Adaptive Skeleton. Zahtzulasa can only use any abilities that deal Fire damage while it has a Fire immunity, and it can only use any abilities that deal Cold damage while it has a Cold immunity. After being hit with three separate instances of fire damage, Zahtzulasa loses its Cold immunity and gains a Fire immunity. After being hit with three separate instances of cold damage, Zahtzulasa loses its Fire immunity and gains a Cold immunity. While under the effects of cold immunity, Zahtzulasa's body is covered with ice crystals. While under the effects of fire immunity, it's body is covered in burn marks and an unusually high heat.

Will of the Undying. Imbued with an undying need to protect the Neveroak from those who wish to take its power, Zahtzulasa will become fully imbued with the power of Varknon, the Lich that became the Neveroak, upon dropping below half of its maximum hit points. Doing so will unlock its spellcasting, refresh all charges of Defender of the Neveroak, and grant it the ability to absorb all Necrotic damage that it takes. Additionally, its bludgeoning resistance will turn into a piercing and slashing resistance, and it loses its Radiant resistance. Finally, it gains an 80 feet flying speed as life is brought back to its wings. Varknon can be seen as a ghost above Zahtzulasa's head that becomes more opaque when spellcasting.

Spellcasting. Varknon, the Lich that empowers Zahtzulasa, is an 18th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 16, +8 to hit with spell attacks). Zahtzulasa has access to the following spells once Varknon grants it full power:

Cantrips (at will): blade ward, ray of frost, fire bolt

1st level (3 slots): shield, false life, silvery barbs

2nd level (3 slots): acid arrow, heat metal, invisibility

3rd level (2 slots): counterspell, erupting earth, fireball

4th level (2 slots): ice storm, death ward

5th level (2 slots): cloudkill, contagion

6th level (1 slot): disintegrate, globe of invulnerability

7th level (1 slot): finger of death, prismatic ray (Fire ray disabled while Cold resistance is active, Cold ray disabled while Fire resistance is active. If the ray is rolled, reroll to choose a different ray.)

8th level (1 slot): antimagic field

9th level (1 slot): power word kill

Multiattack. Zahtzulasa can make three normal attacks as one action. Bite, Claw, Tail, and any of its Minor Breath Weapons are all designated as normal attacks, and can be used interchangeably in any order.

(NE) Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage plus 4 (1d8) cold/fire damage (depending on Zahtzulasa's resistance being either fire/cold respectively).

Claw. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 15 (1d4 + 14) slashing damage.

Tail. Melee Weapon Attack: +10 to hit, reach 20 ft. wide and 10 ft. long area in front of Zahtzulasa. Hit: 10 (1d8 + 6) bludgeoning damage.

Putrid Blast (Minor Breath Weapon). Ranged Weapon attack: +8 to hit, reach 100 ft., one target. Hit: 11 (2d10) poison damage. On a hit, the target must make a DC 15 constitution save or be poisoned, taking 4 (1d8) damage at the start of their turn for one minute. The target can repeat the save at the end of their turn, ending the effect on a success.

Frigid Mist (Minor Breath Weapon). Zahtzulasa exhales a quick puff of freezing cold air forward in a 30 ft. cone. Creatures inside the cone must make a DC 13 Constitution saving throw or take 6 (1d12) cold damage and have their movement speed halved for a minute. On a success, the target is unaffected by the slow and takes half damage. After taking any instance of fire damage, the slow is removed.

Heat Burst (Minor Breath Weapon). Zahtzulasa exhales a rapid burst of heated air that manifests in a small ball of flame with a range of 60 feet. The ball explodes after reaching its target in a 10 foot radius. Creatures inside the radius must make a DC 13 Dexterity saving throw or take 8 (2d8) fire damage. On a success, the target takes half damage. The area struck by the burst is ignited with flames that deal 4 (1d8) damage to anyone who enters the area or starts their turn inside the area.

(NE) Purging Icicle (Minor Breath Weapon) (Recharge 2-6). Zahtzulasa launches forth a chunk of black ice at an area within 120 feet. The icicle can be launched upwards at any target within 30 feet, allowing this attack to ignore cover. The chunk has a size of 10 feet by 10 feet. Any target in the area must make either a DC 16 Strength, Dexterity, or Constitution saving throw (target's choice), taking 16 (3d10) cold damage and 10 (2d10) necrotic damage on a failure, or half as much on a success. Any creature hit has their maximum hit points reduced by a value equivalent to the necrotic damage taken for one hour. If a creature is reduced to 0 hit points by this effect, they are instantly killed.

(NE) Wretched Singe (Minor Breath Weapon) (Recharge 2-6). Zahtzulasa bellows forth three orbs of black fire that travel towards any target it can see within 60 ft., each dealing 3 (1d4 + 1) fire damage and 3 (1d4 + 1) necrotic damage. The target's maximum hit points are reduced by a value equivalent to the necrotic damage taken for one hour. If a creature is reduced to 0 maximum hit points by this effect, they are instantly killed. This spell is completely blocked by the effects of the shield spell.

(NE) Zahtzulasa's Blizzard (Recharge 5-6). Zahtzulasa inhales air on the start of its turn, causing it to lose access to all Legendary Actions it has on this initiative count. Attacks against Zahtzulasa while it is inhaling have advantage, and Zahtzulasa has a Fire vulnerability while charging. Immediately afterwards, three large chunks of ice fall from the sky at locations chosen by the DM. If they land on a creature, the creature must make a DC 14 Dexterity saving throw or take 8 (2d8) bludgeoning damage and 8 (2d8) cold damage. These chunks stay on the map as 5 foot by 5 foot obstructions that can be used as cover. They are melted after taking any amount of fire damage. Once the next round of initiative begins, Zahtzulasa releases the icy blast in a massive 100-foot cone. Each creature in that area must make a DC 17 Constitution saving throw, taking 54 (12d8) cold damage on a failed save, or half as much damage on a successful one. If a creature fails the save, they must roll another DC 17 Constitution saving throw or be frozen in place. A frozen creature can be thawed by an ally with a DC 15 Strength check or by an enemy attack that deals more than 10 of any type of physical damage. Unleashing the Blizzard counts as Zahtzulasa's action for the turn after it began charging it, but it does regain its Legendary actions.

(NE) Zahtzulasa's Eruption (Recharge 5-6). Zahtzulasa begins to well up heat in its body, causing it to lose access to all Legendary Actions it has on this initiative count. Attacks against Zahtzulasa while it's building heat have advantage, and Zahtzulasa has a Cold vulnerability while it is charging. Immediately afterwards, three geysers of heated air burst out from the ground below in random locations that the DM chooses. Any target that is caught in the geyser can either willingly let themselves be launched 50 feet away from Zahtzulasa or make a DC 13 Strength saving throw to resist the effects, being launched 25 feet away on a failed save. In both cases, the launched creature takes 4 (1d8) fire damage and 4 (1d8) bludgeoning damage. Powerful gusts of wind are also emitted from Zahtzulasa, causing creatures to have their movement speed halved when moving towards it and have it doubled when moving away from it. Once the next round of initiative begins, Zahtzulasa creates a massive explosion in a 60 foot radius sphere centered on its body. Any creature within the radius takes 54 (12d8) fire damage. The geysers and strong winds then dissipate. Unleashing the Eruption counts as Zahtzulasa's action for the turn after it began charging it, but it does regain its Legendary actions.

To The Grave. Zahtzulasa's duty to prevent the Neveroak from falling into the hands of others extends even till its last breath. After being dropped to 0 hit points, Zahtzulasa can use its reaction to condemn the creature that struck it down. The creature must succeed on a DC 16 Constitution saving throw or be dropped to 0 hit points immediately. Regardless of whether or not the creature succeeds the save, they are cursed with Varknon's Vengeance, a curse that leaves the target in the cold hands of death. The cursed creature, if killed, resurrects as Varknon in their corpse 1 day after their death. Additionally, over the course of 7 days, the creature begins to wither away, slowly accumulating more and more negative effects as time passes.

Zahtzulasa 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. Zahtzulasa regains spent legendary actions at the start of its turn.

Claw Attack. Zahtzulasa makes a claw attack.

(NE) Relentless Assault. Zahtzulasa makes a claw attack with disadvantage. If it misses, Zahtzulasa makes a bite attack with advantage.

Flight. Zahtzulasa beats its wings and makes a burst of movement in any direction for a distance equivalent to a quarter of its flying speed. This requires Zahtzulasa to have its flying speed unlocked.

Cantrip (costs 2 actions). If Zahtzulasa has its spellcasting unlocked, it casts a cantrip of its choosing.

(NE) Xth-Level Spell (costs X+1 actions). If Zahtzulasa has its spellcasting unlocked, it casts a leveled spell of its choosing with level up to the current amount of Legendary Actions it possesses. This uses up the spell slot as well.

Summon Zombie (costs 2 actions). Zahtzulasa calls forth a Greater Zombie from the ground below to attack the group at any location it can see within 60 feet. The Zombie immediately takes an action. Then, on the next initiative count, the new Zombie rolls initiative to determine its spot in the initiative cycle. Greater Zombie stat block located in my homebrew page.

(NE) Summon Zahtzulasa's Faithful (costs 4 actions). Zahtzulasa calls forth a faithful skeleton warrior to fight by their side. They are summoned directly in front of Zahtzulasa and roll initiative immediately to determine their place in the turn order. Zahtzulasa's Faithful stat block located in my homebrew page.