Champion of Sardia

Ancient Beast. The thick magical scales of the ancient beasts give an advantage on saving throws against magic attacks and is immune to crits. It also cannot be moved against it's will.

Evasion: You can nimbly dodge out of the way of certain dangers. When you’re subjected to an effect that allows you to make a Dexterity saving throw to take only half damage, you instead take no damage if you succeed on the saving throw and only half damage if you fail. You can’t use this feature if you have the Incapacitated condition.

Last stand (1/day): If the Champion hit's 0 HP, goes to 1 instead and recovers 400hp.

Legendary Resistance (4/Day). If Lagrigoyi's bane fails a saving throw, he can choose to succeed instead.

Relentless onslaught: The Champion attacks with reckless abandon, all it's attacks are at advantage, but all attacks against it are always at advantage. The champion on a 19 or 20.

Triple tailed: The three tails act independently of the body, allowing them to grapple or defend. The Champion get a +1 AC for each that isn't either grappling or harassing another creature an creature.

Multiattack. The Champion of Sardia gets to make one Bite, two claw and up to three tail actions.

Bite. Melee Weapon Attack: +19 to hit, reach 5ft., one target. Hit: 21 (2d10 + 10) piercing damage and 21 (3d12) poison damage. The target must also make a DC 27 con save or use it's reaction to attack the nearest creature and contracts The Blue fury disease. 

Rend. Melee Weapon Attack: +19 to hit, reach 10ft., one target. Hit: 23 (2d12 + 10) Slashing damage plus 13 (2d12) poison damage.

Tail Actions:  Can do one action for each of the three tails that are not restrained or grappling a creature.

• Attack: +19 to hit, reach 15 ft., one target. Hit: 23 (2d10 + 10) Slashing damage and the target must make a DC 25 Str or Dex Save or be grappled. Three targets can be grappled at once.
• Harass: The Champion of Sardia can use one of it's tails that didn't attack to give a creature disadvantage on attacks and attacks of opportunity against it have advantage till the champions next turn, or the creature moves more then 15 ft away. If the creature moves away the Champion of Sardia gets two attack of opportunities instead of one.
• Defend: +1 to AC till the start of your next turn.

Onslaught. Recharge 5-6. Melee weapon attack, target must be prone. DC 25 Strength save. Failure take 10d12 slashing damage, 10d12 poison and receive a point of exhaustion. Half as much on a success. 

Dash: The Champion of Sardia takes the Dash action

Fling: If the champion has grappled targets in it's tail it can throw one. The champion of Sardia can either throw it 45ft away to an empty space or do a Ranged Weapon Attack: +19 to hit, range 45/85 ft., One target. Hit: 16 (1d12 + 10) [damage type] damage. Either way the grappled creature is no longer grappled and takes 17 damage.

Rapid recovery (10/Day): The Champion of Sardia Recover 1d10+10 HP.

The Champion of Sardia gets 4 legendary actions per turn

Attack: The Champion of Sardia makes a rend attack.

Brutal Swing (2 actions) recharges on a 5-6: Every creature with 10ft must make up to three DC 27 Dex saves, stopping when they fail one. On a fail they take 6d10+15 Bludgeoning damage and are moved 20ft and knocked prone. Minus 2d10+5 from the damage for each success. 

Pounce:  The Campion of Sardia Leaps 20ft without provoking opportunity attacks. Any creature at it's land location must make a DC 25 Dex save or take 2d6 bludgeoning damage and be knocked prone. A creature may choose to dive out the way, becoming prone but taking no damage, this must be declared before rolling it's save.

Roar of Terror: Champion of Sardia roars. All creatures in 60ft that can hear the champion makes a DC 24 wisdom save. On a fail the creature is frightened of the champion. On a success the are immune to the frightened condition for 24 hours.