Adult Dragon Glass Dragon

Fire Absorption. Whenever the dragon is subjected to fire damage, it takes no damage and instead regains a number of hit points equal to the fire damage dealt.

Immutable Form. The dragon is immune to any spell or effect that would alter its form.

Magic Resistance. The dragon has advantage on saving throws against spells and other magical effects.

Magic Weapons. The dragon's weapon attacks are magical.

Enhanced Magic Bane. If a spell is cast within 120 feet of the dragon, friend or foe, it's next attack will deal an additional +2 per spell level. [stackable] An attack, regardless if it connects or not, will consume all stacks of magic bane.

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

Multiattack. The dragon makes three melee attacks.

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 7) piercing damage.

Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage.

Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 16 (2d8 + 7) bludgeoning damage.

Frightful Presence. Each creature of the dragon's choice that is within 120 feet of the dragon and aware of it must succeed on a DC16 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 dragon's Frightful Presence for the next 24 hours.

Nova Breath(Requires +25 Magic Bane stacks); The dragon produces a beam of magical energy in a 60-foot-cone. Each creature in that area must make a DC18 dexterity saving throw, taking 58 (6d10+25) force damage on a failed save, or half as much damage on a successful one. Does not apply additional damage from Magic Bane.

The dragon can take 3 legendary action, choosing from the options below. Only one legendary actions 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.

Detect. The dragon makes a wisdom (Perception) check.

Tail Attack. The dragon makes a tail attack.

Wing Attack (Costs 2 Actions). The dragon beats its wings. Each creature within 10 feet of the dragon must succeed on a DC19 Dexterity saving throw or take 14 (2d6+7) bludgeoning damage and be knocked prone. The dragon can then fly up to half its flying speed.