Ancient Solar Dragon

Gargantuan dragon, typically neutral

Armor Class

18 (natural armor)

Hit Points

425 (23d20 + 184)

Speed

walk 30 ft., fly 120 ft.(hover), canHover true ft.

Saves

wis +11, con +15, dex +9, cha +10

Skills

stealth +9, perception +18

Senses

darkvision 240 ft.

Languages

Draconic

Challenge

21

Proficiency Bonus

+7

Flyby

The dragon doesn't provoke opportunity attacks when it flies out of an enemy's reach.

Legendary Resistance (3/Day)

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

Nebulous Thoughts

Magical attempts to read the dragon's mind or glean its thoughts fail automatically.

Siege Monster

The dragon deals double damage to objects and structures.

Unusual Nature

The dragon doesn't require air.

Actions

Multiattack

The dragon makes one Bite attack and one Tail attack.

Bite

Melee Weapon Attack: +16 to hit, reach 20 ft., one target. Hit: 19 (3d6 + 9) piercing damage plus 10 (3d6) radiant damage.

Tail

Melee Weapon Attack: +16 to hit, reach 20 ft., one target. Hit: 13 (1d8 + 9) bludgeoning damage.

Photonic Breath (Recharge 5-6)

The dragon exhales a flashing mote of radiant energy that travels to a point the dragon can see within 240 feet of itself, then blossoms into a 40-foot-radius sphere centered on that point. Each creature in the sphere must make a DC 23 Constitution saving throw, taking 66 (12d10) radiant damage on a failed save, or half as much damage on a successful one.

Legendary actions

Legendary Actions (3/Turn)

The Ancient Solar Dragon can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. The Ancient Solar Dragon regains spent legendary actions at the start of its turn.

Tail Attack

The dragon makes one Tail attack.

Blinding Brilliance (Costs 2 Actions)

The dragon emits magical light in a 30-foot-radius sphere centered on itself. Each creature in this area must succeed on a DC 23 Wisdom saving throw or be blinded until the end of its next turn.