Avoidance. If the demilich is subjected to an effect that allows it to make a saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Turn Immunity. The demilich is immune to effects that turn undead.

Howl (Recharge 5–6). The demilich emits a bloodcurdling howl. Each creature within 30 feet of the demilich that can hear the howl must succeed on a DC 15 Constitution saving throw or drop to 0 hit points. On a successful save, the creature is frightened until the end of its next turn.

Life Drain. The demilich targets up to three creatures that it can see within 10 feet of it. Each target must succeed on a DC 19 Constitution saving throw or take 21 (6d6) necrotic damage, and the demilich regains hit points equal to the total damage dealt to all targets.

It can cast Dark Star once per day, requiring no material components. Using the spell, it creates a radius large enough to consume as many hostile creatures as possible (even if this includes its own allies). Once it casts dark star, the demilich concentrates on the spell. Damage to the glass beacon can’t break the demilich’s concentration.