Crystal Core. if its core is broken the dragon dies (Core Hp: 250 AC:15)
Multi attack. Make 2 claw attacks and 1 bite attack per turn.
Claw. Melee Weapon Attack: +9 to hit, reach 5 ft., 1 target. Hit: 27 (2d10 + 15) [Slashing] damage.
Bite. Melee Weapon Attack: DC 15 Dex save, reach 15ft in front., All targets in range . Hit: 17 (2d10 + 5) [Slashing] damage and 17 (2d10 + 5) [Necrotic] damage. if grounded, the ground becomes difficult terrain
Tail sweep. Melee Weapon Attack: +10 to hit, reach 15 ft., all targets in range. Hit: 34 (4d10 + 10) [Bludgeoning] damage.
Bone Shrapnel. RangedWeapon Attack: +8 to hit, range 30/60 ft line., all targets. Hit: 15 (1d8 + 10) [Piercing] damage & 15 (1d8 + 10) [Necrotic] damage.
Breath. RangedWeapon Attack: DC16 Dex Save, range 60ft Cone., All target. Hit: 32 (2d10 + 20) [Necrotic] damage & 32 (2d10 + 20) [Poison] damage. Half dmg on saves. Recharge on 5&6
4 legendary actions
Breath recharge (Costs 1 Actions). roll to recharge breath attack
Roar (Costs 2 Actions). all players make WIS saving roll (DC: 12) failed saves are Frightened