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

Life Suppression. Creatures within 60 feet of Sammaster can't regain Hit Points.

Magic Resistance. Sammaster has Advantage on saving throws against spells and other magical effects.

Soul Gem. Sammaster has a magical soul gem as his dracolich heart. The gem can't be damaged or removed until he is reduced to 0 Hit Points. If Sammaster is reduced to 0 Hit Points, his dracolich form dissolves to dust. After 1d10 days, he appears in an unoccupied space within 5 feet of his soul gem (so long as the gem still exists), using the Sammaster (Lich Form) stat block. The gem is a Tiny object that has AC 20; HP 50; and Immunity to Acid, Necrotic, Poison, and Psychic damage. The gem regains all its Hit Points at the end of every turn, but it turns to dust if reduced to 0 Hit Points.

Spellcasting. Sammaster casts one of the following spells, requiring no Material components and using Intelligence as the spellcasting ability (spell save DC 21, +13 to hit with spell attacks):

At will: Blight, Detect Magic, Dispel Magic, Mage Hand, Prestidigitation, Ray of Sickness (level 6 version)

1/day each: Create Undead (level 8 version), Power Word Kill

2/day each: Dimension Door, Speak with Dead

Multiattack. Sammaster makes three Rend attacks. He can replace one attack with a use of Spellcasting to cast Blight or Ray of Sickness (level 6 version).

Rend. Melee Attack Roll: +14, reach 10 ft. Hit:18 (2d10 + 7) Slashing damage plus 18 (4d8) Necrotic damage.

Corroding Breath (Recharge 5–6). Constitution Saving Throw: DC 20, each creature in a 90-foot Cone. Failure: 52 (8d12) Acid or Necrotic damage (Sammaster's choice). Success: Half damage.

Pounce. Sammaster moves up to half his Speed, and he makes one Rend attack.

Sickening Ray. Sammaster uses Spellcasting to cast Ray of Sickness (level 6 version).

Terrifying Presence. Wisdom Saving Throw: DC 21, each creature in a 20-foot Emanation originating from Sammaster. Failure: 13 (2d12) Psychic damage, and the target has the Frightened condition until the end of its next turn. Failure or Success: Sammaster can't take this action again until the start of his next turn.