Apophis

God of Chaos. Apophis is immune to status effects and bludgeoning, piercing, and slashing damage from non-magical weapons.

Legendary Resistance (3/Day). If Apophis fails a saving throw, he can choose to succeed instead.

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

Kingslayer. Apophis deals double damage to creatures regarded as leaders, kings, etc.

Uncanny Nimbleness. Apophis's movement cannot be altered or prevented. He ignores difficult terrain.

Multiattack. Apophis makes four attacks: two with his bite, two with his claws. He then may use his Primordial Darkness or Earthquake attack.

Bite. Melee Weapon Attack: +19 to hit, reach 10 ft., one target. Hit: 36 (4d12 + 10) piercing damage. If the target is a creature, it is inflicted with Dreadful Madness. Creatures with Dreadful Madness may make a DC 20 Wisdom saving throw at the start of each of their turns to attempt to end the affliction. On a failure, they take 4d8 psychic damage. Whenever a creature with Dreadful Madness takes an action, it rolls a d10. On a 1, it instead attempts to attack the creature nearest to it.

Tail. Melee Weapon Attack: +19 to hit, reach 20ft., one target. Hit: 24 (4d6 + 10) bludgeoning damage. If the target is a creature, it must succeed on a DC 20 Strength saving throw or be knocked prone.

Primordial Darkness. Apophis exhales fumes of chaos from the genesis of the universe. All creatures within a 120-foot cone must succeed on a DC 25 Charisma saving throw or take 6d10 psychic damage (or half as much on a successful one) and be inflicted with Dreadful Madness. Creatures killed by this feature are dissolved into a puddle of murky-black darkness and cannot be revived.

Earthquake. Apophis shakes the ground, causing great tremors to rumble in a 180 foot radius around him. All terrain in the area becomes difficult terrain, and creatures caught into the blast must succeed on a DC 20 Dexterity saving throw or take 6d10 bludgeoning damage (or half as much on a successful one) and be thrown 60 feet into the air.

When Apophis dies, this terrain returns to normal after 4d10 years.

Apophis 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. Apophis regains spent legendary actions at the start of its turn.

Attack. Apophis makes one bite attack or tail attack.

Move. Apophis moves up to half his speed.

Teleport (Costs 2 Actions). Apophis dissolves into inky-black shadows and teleports to a location he can see. Until the end of his next turn, he is invisible.

Alluring Gaze (Costs 3 Actions). Apophis attempts to beguile a creature. That creature must succeed on a DC 20 Charisma saving throw or be Charmed. Charmed creatures may repeat this saving throw at the start of each of their turns. While they are Charmed, Apophis commands creatures on their turn, making all actions for them.