Bea's Brilliant Beautiful Beast (Full power)

Amphibious. The dragon can breathe air and water.

Legendary Resistancen't (3/Day). If the dragon fails a saving throw, it can choose to add its proficiency bonus (+7) to that save.

Adamantine Scales. The dragon's scales have been plated in pure adamantine, protecting it from critical hits. When the dragon gets hit by a critical hit, it becomes a normal hit, however, the dragons AC decreases by 1. Additionally, if the dragon takes over 30 acid damage in one round, then its AC also goes down by 1. This feature ceases to function once its AC becomes 20 or lower. This feature also ceases to function when the dragon is in mythic form.

Adamantine coated weapons. All of the dragons natural weapons automatically are critical hits upon hitting an object.

Siege Monster. The dragon deals double damage to objects and structures.

Heavy. Due to the dragon being plated in adamantine, it is far heavier than it should be. The dragon removes 10ft from any affect that would push or pull the dragon.

Antimagic eye. (Mythic form only). While this eye is out, there is an antimagic field in a 20ft radius emerging from the dragons. Any spell of 5th level or lower that enters the spell automatically fails, and any creature under the effect of a spell of 5th level or lower has that effect suppressed while in the aura. Area of effects created by spells also fail to pierce the aura. Certain effects that could be argued as not part of the spell can pierce the aura at dm discretion. When the dragon hits someone with a natural weapon attack, they must make a concentration check. On a fail, they are unable to cast spells until the end of their next turn. If the eye takes 50 or more damage from a single attack, this feature fails to function until the start of the dragons next turn.

Multiattack. The dragon can use its Frightful Presence. It then makes three attacks: one with its bite and two with its claws. Alternately, it can use any 2 attacks.

Bite. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) piercing damage.

Claw. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 17 (2d6 + 10) slashing damage.

Tail. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage.

Stomp. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 37 (5d10+10) bludgeoning damage. This attack can only be made against a prone target.

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 DC 20 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.

Telegraphed Attack. The dragon takes one turn to wind up an attack. When the dragon takes this action, it cannot take any attacks, reactions, or attacks granted by legendary or mythic actions until the start of its next turn. When it starts its next turn, all creatures within 20 feet of the dragon must make a DC 20 Dexterity saving throw, taking 64 (8d10+20) bludgeoning damage on a failed save and half as much on a success.

Breath Weapons (Recharge 6) The dragon uses one of the following breath weapons.

Magic Breath. The dragon exhales fire in a 90-foot cone. Each creature in that area must make a DC 20 Dexterity saving throw, taking 71 (13d10) force damage on a failed save, or half as much damage on a successful one.  When the dragon is in its Mythic form, It randomly determines an effect from one of the open eyes. All creatures who fail their save against the breath weapon are also automatically targeted by the ray.

(Mythic form only) Eye ray. The dragon fires one eye ray, choosing randomly from an open eye.

The 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.

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 15 feet of the dragon must succeed on a DC 20 Dexterity saving throw or take 17 (2d6 + 10) bludgeoning damage and be knocked prone.

Sped up attack (Costs 3 Actions) (1 time per long rest). The dragon uses its choreographed attack if it is charging it up.

When the Dragon reaches 0 hit points after 3 rounds, the dragon mutates. 11 eyes appear on the dragons body. At the start of each of the dragons turns, roll a d4 for each eye. On an odd, the eye is closed and cannot be used or target by attacks, spells, and has total cover. On an even, the eye is open, can be targeted, and the dragon can use actions relating to that eye. There is an antimagic eye, and 10 more correlating to the list bellow. The antimagic eye is not revealed until all other eyes are destroyed. Finally, the antimagic eye can use any ray it chooses.

1. Charm Ray. The targeted creature must succeed on a DC 19 Wisdom saving throw or be charmed by the beholder for 1 hour. The target can repeat the saving throw at the start of each of its turns, ending the effect on itself on a success. or until the beholder harms the creature.
2. Paralyzing Ray. The targeted creature must succeed on a DC 19 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
3. Fear Ray. The targeted creature must succeed on a DC 19 Wisdom saving throw or be frightened for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
4. Slowing Ray. The targeted creature must succeed on a DC 19 Dexterity saving throw. On a failed save, the target’s speed is halved for 1 minute. In addition, the creature can’t take reactions, and it can take either an action or a bonus action on its turn, not both. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
5. Enervation Ray. The targeted creature must make a DC 19 Constitution saving throw, taking 36 (8d8) necrotic damage on a failed save, or half as much damage on a successful one.
6. Telekinetic Ray. If the target is a creature, it must succeed on a DC 19 Strength saving throw or the beholder moves it up to 30 feet in any direction. It is restrained by the ray’s telekinetic grip until the start of the beholder’s next turn or until the beholder is incapacitated. If the target is an object weighing 300 pounds or less that isn’t being worn or carried, it is moved up to 30 feet in any direction. The beholder can also exert fine control on objects with this ray, such as manipulating a simple tool or opening a door or a container.
7. Sleep Ray. The targeted creature must succeed on a DC 19 Wisdom saving throw or fall asleep and remain unconscious for 1 minute. The target awakens if it takes damage or another creature takes an action to wake it. This ray has no effect on constructs and undead.
8. Petrification Ray. The targeted creature must make a DC 19 Dexterity saving throw. On a failed save, the creature begins to turn to stone and is restrained. It must repeat the saving throw at the end of its next turn. On a success, the effect ends. On a failure, the creature is petrified until freed by the greater restoration spell or other magic.
9. Disintegration Ray. If the target is a creature, it must succeed on a DC 19 Dexterity saving throw or take 45 (10d8) force damage. If this damage reduces the creature to 0 hit points, its body becomes a pile of fine gray dust. If the target is a Large or smaller non-magical object or creation of magical force, it is disintegrated without a saving throw. If the target is a Huge or larger object or creation of magical force, this ray disintegrates a 10-foot cube of it.
10. Death Ray. The targeted creature must succeed on a DC 19 Dexterity saving throw or take 55 (10d10) necrotic damage. The target dies if the ray reduces it to 0 hit points.

The antimgaic eye has an AC of 20 and 300 hit points, while the rest have 18 AC and 100 hit points. When an eye is reduced to zero hit points, It no longer functions.

Additionally, the dragon gains the following mythic actions, which it can use in place of a legendary action.

Eye beam. (Costs 2 actions) The dragon uses 2 eye rays choosing from one of the open eyes. These rays cannot target the same creature.

Open/close. The dragon can open or close one of its eyes. It cannot do this for its antimagic eye.