Ulamog

If Ulamog fails a saving throw, it can choose to succeed instead.

Ulamog has advantage on saving throws against spells and other magical effects.

Ulamog's weapon attacks are magical.

Melee Attack Roll: +17 to hit, reach 10 ft., one target. Hit: 31 (6d6 + 10) bludgeoning damage. If the target is a creature, it must succeed on a DC 15 Constitution saving throw or be stunned until the end of Ulamog's next turn.

Ranged Spell Attack Roll: +15 to hit, range 600 ft., one target. Hit: 24 (7d6) damage of one of the following types (empyrean's choice): acid, cold, fire, force, lightning, radiant, or thunder.

Ulamog makes one attack.

Ulamog bolsters all nonhostile creatures within 120 feet of it until the end of its next turn. Bolstered creatures can't be charmed or frightened, and they gain advantage on ability checks and saving throws until the end of Ulamog's next turn.

Ulamog strikes the ground with its maul, triggering an earth tremor. All other creatures on the ground within 60 feet of Ulamog must succeed on a DC 25 Strength saving throw or be knocked prone.

Ulamog's innate spellcasting ability is Charisma (spell save DC 23, +15 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

At will: greater restoration, pass without trace, water breathing, water walk

1 each/day: commune, dispel evil and good, earthquake, fire storm, plane shift (self only)