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

Spellcasting. Vlindarian is a 18th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 20, +12 to hit with spell attacks). It has following spells prepared:

Cantrips (at will): fire bolt, prestidigitation, ray of frost, light

1st level (4 slots): detect magic, magic missile, shield

2nd level (3 slots): mirror image, scorching ray, enlarge reduce, blindness/deafness

3rd level (3 slots): animate dead, fireball, dispel magic

4th level (3 slots):  arcane eye, resilient sphere, polymorph

5th level (2 slots): scrying, telekinesis

6th level (1 slots): globe of invulnerability, freezing sphere

7th level (1 slots): teleport, prismatic spray

8th level (1 slot): antimagic field, power word stun, dominate monster

9th level (1 slot): power word kill

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 14 (4d6) piercing damage.

Eye Rays. Vlindarian shoots all of the three magical eye rays, choosing one target for each it can see within 120 feet of it:

1. Disintegration Ray. If the target is a creature, it must succeed on a DC 20 Dexterity saving throw or take 45 (10d8) force damage. If this damage reduces the creature to 0 hit points, its body becomes a pile of fine gray dust.

2. Petrification Ray. The targeted creature must make a DC 20 Dexterity saving throw. On a failed save, the creature begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified until freed by the greater restoration spell or other magic.

If the target is a Large or smaller nonmagical object or creation of magical force, it is disintegrated without a saving throw. If the target is a Huge or larger object or creation of magical force, this ray disintegrates a 10-foot cube of it.

3. Charm Ray. The targeted creature must succeed on a DC 20 Wisdom saving throw or be charmed by the beholder for 1 hour, or until the beholder harms the creature. 

Vlindarian can take 3 legendary actions, using the options below. It can take only one legendary action at a time and only at the end of another creature’s turn. The beholder regains spent legendary actions at the start of its turn.

Eye Ray. Vlindarian uses one random eye ray.

Cantrip. Vlindarian casts a cantrip.