Archtempered Nergigante

Legendary Resistance (4/Day). If the nergigante fails a saving throw, it can choose to succeed instead.

Flashpod Resistance. The nergigante has advantage on being blinded by items or equipment, whether magical or not.

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

Spiked Regrowth. The nergigante has spikes covering its body, granting it +2 AC. These spikes regrow at the start of the nergigante's turn if they are lost. After using an action or legendary action, the nergigante can use its spiked explosion as a bonus action.

Multiattack. The nergigante can use its frightful presence. It then makes four attacks: one with its bite, one with its horn, and two with its claws.

Frightful Presence. Each creature of the nergigante's choice that is within 120 feet of the nergigante 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 nergigante's Frightful Presence for the next 24 hours.

Bite. Melee Weapon Attack: +16 to hit, reach 5 ft., one target. Hit: 36 (8d6 + 8) piercing damage.

Horn. Melee Weapon Attack. +16 to hit, reach 10 ft., one target. Hit: 41 (6d10 + 8) bludgeoning damage.

Claw. Melee Weapon Attack. +16 to hit, reach 10 ft., one target. Hit: 22 (4d6 + 8) slashing damage.

Wings. Melee Weapon Attack. +16 to hit, reach 10 ft., one target. Hit: 41 (6d10 + 8) piercing damage.

Tail. Melee Weapon Attack. +15 to hit, reach 15 ft., one target. Hit: 30 (4d10 + 8) bludgeoning damage.

Meteor Crash (Recharge 5-6). The nergigante leaps into the air using its wings to hover briefly and comes crashing down in a 15-foot square area within 60 feet of it. Each creature in that area must make a DC 22 Dexterity saving throw, taking 73 (21d6) bludgeoning damage on a failed save, or half as much damage on a successful one.

Spiked Explosion. The spikes on the nergigante explode outward, removing the AC bonus it receives spiked regrowth and strikes all targets within 35-foot sphere of it. Each creature in that area must make a DC 22 Dexterity saving throw, taking 11 (2d10) piercing damage on a failed save or half as much on a successful one.

Dragon Eater. The nergigante feeds on the corpse of a dragon. A Large or smaller dragon is consumed whole, while the nergigante can feed on a Huge or bigger dragon for up to 30 seconds. For each round the Nergigante feeds on a dragon, it heals for an amount equal to the dragons Challenge rating.

Aggressive Swipe. The nergigante makes a Claw or Tail attack. The nergigante can make this bonus action before it makes its Multiattack.

Tempered Rush (Recharge 6). For the next 1 minute, the Nergigante's speed(s) increase by 40 feet each, its attacks deal 2 additional damage, and it has advantage on saving throws against being restrained, grappled, poisoned, incapacitated, or stunned. 

The nergigante 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 creatures turn. The nergigante regains spent legendary actions at the start of its turn.

Move. The nergigante moves up to its speed without provoking opportunity attacks.

Tail Attack. The nergigante makes a tail attack.

Wing Attack. The nergigante makes a wing attack.

Trample (Costs 2 Actions). The nergigante moves up to its speed, during this move it may move through other creatures without provoking attacks of opportunity. Any creatures the nergigante moves through must succeed on a DC 21 Dexterity saving throw or take 30 (4d10 + 8) bludgeoning damage and be knocked prone.