Ancient knight dragon

Armor Class 25 plate

Hit Points 560 (20d12 + 320)

Speed 120 ft., Walk 60 ft.

STR

30 (+10)

DEX

30 (+10)

CON

26 (+8)

INT

24 (+7)

WIS

25 (+7)

CHA

30 (+10)

Saving Throws STR +18, DEX +18, CON +16

Skills +22, +13, +13

Damage Vulnerabilities Acid, Fire, Lightning

Damage Resistances Bludgeoning, Cold, Radiant

Damage Immunities Necrotic, Piercing

Condition Immunities , , ,

Senses , Passive Perception 25

Languages Draconic

Challenge 28 (120,000 XP)

Proficiency Bonus +8

Traits

Adamantine plating: any critical hit on the ancient knight dragon will be a normal attack

Serrated blades: if a person is in 5ft of the ancient knight dragon when it moves, they take 1d10 damage

Multiattack: the ancient knight dragon can make two of any action it has

Actions

Claws +20 to hit (3d8+20)

Tail +20 to hit (6d4+20)

Blade storm: The target must roll a DC DEX saving throw of 23, on failure the target receives (9d8) points of damage

Martyrdom: +12 to hit (12d6+12)

Bladed wings: +20 to hit (2d10+20)

Chromatic blast +12 to hit (5d8+12)

Bonus Actions

Martyrdom: +12 to hit (12d6+12)

Opportunity attack

Reactions

Baneful defense: The ancient knight dragon can choose the following effects

.Increase the AC needed to hit by 1d6

.reduce the attackers damage by 2d6

Legendary Actions

Ultimate Resistance: The ancient knight dragon, on a failure in a saving or check can choose to succeed.

Inner adamantium: (once per long rest) When the ancient knight dragon reaches 0hp it can regain to 300hp

Lair and Lair Actions

In the Batol of Uvuros, The ancient knight dragon can at will use the following attacks

Blade storm: The target must roll a DC DEX saving throw of 23, on failure the target receives (9d8) points of damage