Calamity Ganon

Amphibious. Calamity Ganon can breathe air and water.

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

Impervious. Once he gets to 1/4 of his total health, he will be impervious to any attacks until you parry one of his lasers, after you do, he is no longer impervious until the end of the person who parried the attack's next turn

Multiattack. Calamity Ganon can use its Frightful Presence. It then makes two attacks of it's choice.

Frightful Presence. Each creature of ganon's choice that is within 120 feet of ganon and aware of it must succeed on a DC 16 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 ganon's Frightful Presence for the next 24 hours.

Guardian Laser (Recharge 5–6). Ganon charges up and shoots a glowing laser in a 60-­foot line that is 2 feet wide. Each creature in that line must make a DC 18 Dexterity saving throw, taking 54 (20d10) necrotic damage on a failed save, or half as much damage on a successful one.

Windblight ganon's gusts Ganon shoots the gusts that windblight ganon uses, knocking everyone near him 10 feet back and knocking them over on a failed DC 14 dex save

Waterblight ganon's spear Ganon thrusts the spear towards someone, dealing 10d10 if it hits(+11 to hit)

Fireblight ganon's axe Ganon swing his axe straight at someone, dealing 10d12 fire damage if it hits (+8 to hit)

Thunderblight ganon's pillars Ganon throws metal pillars in the arena, and if someone stays near one for too long they will get electrocuted, dealing 8d10 lightning damage. These can be redirected towards ganon with magnesis