Ancient Stained Glass Dragon

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

Multiattack. The stained glass dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 7 (2d6) fire damage.

Claw. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 15 (2d6 + 8) slashing damage.

Tail. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 17 (2d8 + 8) bludgeoning damage.

Radiant Breath (Recharge 5–6). The dragon exhales fire in a 60-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 63 (18d6) radiant damage on a failed save, or half as much damage on a successful one.

Frightful Presence. Each creature of the Stained glass dragon's choice that is within 120 feet of the Stained glass dragon and aware of it must succeed on a DC 21 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the Stained glass dragon's Frightful Presence for the next 24 hours.

The Stained glass dragon 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. The dragon regains spent legendary actions at the start of its turn.

Glass Shrapnel (costs 1 action). The Stained glass dragon makes a ranged melee attack  sending shards of hardened glass at a creature. (+14 to hit, range 30/120, 3d10+6 piercing damage )

Wing Attack (Costs 2 Actions). The swarm beats its wings. Each creature within 10 feet of the dragon must succeed on a DC 22 Dexterity saving throw or take 15 (2d6 + 8) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.

Radiant Burst(Cost 3 Actions). The stained glass dragon causes it's scales and hide to release vibrant red light. Each creature within 20 feet of the stained glass dragon must succeed on a DC 17 con save or be blinded. The dragon can then fly with Half of it's fly speed to get into the air.