Argonasas, elemental form

Air Form. The elemental can enter a hostile creature’s space and stop there. He can move through a space as narrow as 1 inch wide without squeezing if air could pass through that space, but he will lose his armor. A creature that hits the elemental with a range attack while without 20 feet and within 30 feet of it takes 5 (1d10) force damage. 

Fire form. A creature that touches the elemental or hits it with a melee attack while within 10 feet of it takes 9 (2d8) fire damage. In addition, the elemental can enter a hostile creature's space and stop there. The first time it enters a creature's space on a turn, that creature takes 14 (2d12) fire damage and catches fire; until someone takes an action to douse the fire, the creature takes 7 (2d6) fire damage at the start of each of its turns.

Water Form. The elemental can enter a hostile creature’s space and stop there. He can move through a space as narrow as 1 inch wide without squeezing if water could pass through that space, but he will lose his armor. A creature that hits the elemental with a range attack while without 10 feet and whitin 20 feet of it takes 3 (1d6) force damage. 

Earth form. A creature that hits the elemental with a meelee attack while within 20 feet of it takes 10 (3d6) force damage. The first time it enters a creature's space on a turn, that creature takes 7 (2d6) force damage and ended up into an 30 feet square earthquake; until someone gets out of the area, the creature takes 5 (1d10) fire damage at the start of each of its turns.

Amphibious. Argonasas can breathe air and water. 

Earth Glide. Argonasas can burrow through nonmagical, unworked earth and stone. While doing so, the elemental doesn't disturb the material it moves through.

Ice Walk. Argnasas can move across and climb icy surfaces. Additionally, difficult terrain composed of ice or snow doesn't cost it extra movement.

Elemental terrain. An elemental square from 30 feet environs the elemental, this is counted as difficult terrain.

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

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

Siege Monster. Argonasas deals double damage to objects and structures.

limited Magic immunity. Argonasas won't be affected by spells fom level 5 or lower unless Argonasas chooses to be affected.  

Regeneration. At the start of his turn, Argonasas heals 50 HP.

Magic weapons. Argonasas' attacks will be counted as magic.

Innate Spellcasting. Argonasas innate spellcasting ability is Intellegence (spell save DC 20, +10 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

At will: Ice wall, Fire Storm, Argonasas' darkness, eye of argonasas.

2/ day: Bones of the earth, Delayed Blast Fireball, chain lightning.

3/ day: Meteor swarm, sunburst, Arcane hand, dark poisonball, summon elemental.

Special, at will: Colorfull tentacles

One eye. Argonasas has disadvantage on checks that rely on sight.

Multiattack. Argonasas makes a slam attack and two touch attacks.

Slam. Meelee attack: +17 to hit, range 20 ft. long, 10 ft. broad., max 3 targets. Hit: 36 (4d12 +10) bludgeoning damage.

Element attack. Meelee attack: +24 to hit, range 50 feet. 2 targets., Hit: 15 (2d6 +8) cold damage, 17 (2d6 +10) force damage, 19 (2d8 +10) bludgeoning damage, 21 (2d10 +10) fire damage. 

Touch. Melee Attack: +14 to hit, reach 5 ft., one target. Hit: 17 (2d6 + 10) fire damage. If the target is a creature or a flammable object, it ignites. Until a creature takes an action to douse the fire, the target takes 9 (2d8) fire damage at the start of each of its turns.

Dark feather. Ranged Attack: +14 to hit, range 60 ft., three targets. Each target which is hit by the feathers takes 10 (3d6) poison damage for every feather it's hit by, they will take the damage for the next four turns. If a creature has a strength below 15, he will take 5 (1d10) extra damage every turn.

Whirlwind (Recharge 5). Each creature in the elemental's space must make a DC 17 Strength saving throw. On a failure, a target takes 42 (12d6) bludgeoning damage and is flung up 40 feet away from the elemental in a random direction and knocked paralized and prone for two turns. If a thrown target strikes an object, such as a wall or floor, the target takes 10 (3d6) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 17 Dexterity saving throw or take the same damage and be knocked paralized and prone.

If the saving throw is successful, the target takes half the bludgeoning damage and isn't flung away or knocked paralized and prone.

Eruption (recharge 7). Each creature within 60 feet of Argonasas must make a DC 22 Strength saving throw. On a failure, a target takes 59 (5d10 +6) fire damage and is flung up to 30 feet away from the elemental in a random direction and knocked paralized and unconscious for two turns. If a thrown target strikes an object, such as a wall or floor, the target takes 14 (2d12) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 22 Dexterity saving throw or take the same damage and be knocked paralized, unconscious and incapacitated for two turns. 
If the saving throw is successful, the target takes half the fire damage and isn't flung away and knocked paralized and unconscious.

The 50 feet square is dispersed by Argonasas, the fire will spread with a speed of 20 feet in a turn. When a creature ends in the square, it have to make a DC 17 Strength saving throw, on a failure it will take 25 (2d10 + 15) fire damage and catches fire; until someone takes an action to douse the fire, the creature takes 14 (2d12) fire damage at the start of each of its turns. When the fire is doused, the creature won't take fire damage from the fire square the next two turns.
If the saving throw is succesful, the target takes half the fire damage. It takes 9 (2d8) fire damage at the start of each of its turns.
After 5 turns, the fire stops dispersing, the fire will only disapear when Argonasas dies or when he stops the attack.

Tsunami (recharge 5). Each creature within 30 feet of Argonasas must make a DC 22 Strength saving throw. On a failure, a target takes 39 (10d8) force damage and is flung 50 feet away from the elemental in a random direction and knocked paralized for one turn. If the target is thrown at another creature, that creature must succeed on a DC 22 Strength saving throw or take the same damage.
If the saving throw is successful, the target takes half the force damage and isn't flung away and knocked paralized.
Each creature within 60 feet of Argonasas must make a DC 17 Strength saving throw. On a failure, a target takes 30 (3d10 +7) force damage and is flung 20 feet away from the elemental in a random direction and knocked paralized for one turn. If the target is thrown at another creature, that creature must succeed on a DC 17 Strength saving throw or take the same damage.
If the saving throw is successful, the target takes half the force damage and isn't flung away and knocked paralized. When Argonasas wants to activate tsunami and eruption was active, the eruption disappears. 

Earthquake (recharge 7). Each creature within 20 feet of Argonasas must make a DC 22 saving throw. On a failure a target takes 75 (12d12 + 15) bludgeoning damage and is flung up to 60 feet away from the elemental in a random direction and knocked paralized, unconscious and restrained for three turns. If a thrown target strikes an object, such as a wall or floor, the target takes 17 (2d10 +6) bludgeoning damage for every 15 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 22 Dexterity saving throw or take the same damage and be knocked paralized, unconscious and restrained for two turns. 
If the saving throw is successful, the target takes half the bludgeoning damage and is flung away up to 20 feet away from the elemental in a random direction and knocked paralized for one turn. If a thrown target strikes an object, such as a wall or floor, the target takes 14 (2d12) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 10 Dexterity saving throw or take the same damage and be knocked paralized for one turn. 

Take over. When a creature within 80 feet of Argonasas is hurt, Argonasas gains the HP the creature lost. When he attacks a creature by himself, he won't gain the lost HP from that creature.

Range resistance. When a ranged attack hurts Argonasas, he makes a DC 17 saving throw. On a failure, Argonasas takes al the damage. If the saving throw is succesful, he returns the attack and hits the original shooter. The shooter takes half damage.

Transformation. When Argonasas' elemental form dies, he transforms into Argonasas, undead form. When he transforms, he can teleport to a place in a 10.000 ft. radius.

Argonasas can take 3 legendary actions, choosing from the actions below. Argonasas regains his spent legendary action at the start of his turn.

 Rampage mode. Argonasas will go to his rampage mode with the following effects:

1. All Argonasas' ways of movement increase with 40 feet.
2. All Argonasas' attacks will do double damage.
3. "limited Magic immunity. Argonasas won't be affected by spells fom level 5 or lower unless Argonasas chooses to be affected."  will change to:
   "limited Magic immunity. Argonasas won't be affected by spells fom level 7 or lower unless Argonasas chooses to be affected."
4. Any creature that uses a meelee attack on Argonasas takes 72 (16d8) bludgeoning damage.
5. Any creature that uses a ranga attack on Argonasas takes 52 (8d12) force damage.
6. Argonasas doesn't have recharge while using his rampage mode.
7. Argonasas won't have to recharge his attacks while using his rampage mode.

Complete control. Argonasas shoots a 90 feet cone with all four elements in it. Every creature in the cone takes 25 (5d10) force damage, 25 (5d10) fire damage, 25 (5d10) bludgeoning damage and 25 (5d10) cold damage. If a target is a flammable object, it ignites and turns to ashes immediately. If a target is a creature, it catches fire; until someone takes an action to douse the fire, the creature takes 25 (5d10) fire damage every turn.

The red lightning flash. Argonasas uses his red whirlwind with which he can control everybody he wants. With that power, he tries to break his enemies minds. All creatures in a 300 ft., radius will take 210 (20d20) psychic damage, this ignores resistance and immunity for psychic damage.

Argonasas can take 3 mythic actions, choosing from the actions below. Argonasas won't regain his spent mythic actions

Lost soul. Argonasas uses the emotions of Midancaros to let everyone feel his pain. every creature within a 100 ft., range takes 90 (16d10) psychic damage. This attack ignores resistance, but creatures with immunity won't feel anything

Demon gate. Argonasas can open a gate to another dimension, he can use this three times in a battle. When he went to the demon dimension, he heals 100 HP at once. Besides using it appart, he can stay there for three turns and return with 350 HP extra. When he returns from the gate, he can teleport to a place in a 90 ft., radius from the place where he went to the dimension. 

Hell's fire. Argonasas shoots a 60 feet cone with purple and black flames. Every creature in the cone takes 67 (7d12) fire damage. If the target is a flammable object or creature, it catches fire; until someone takes an action to douse the fire, the creature takes 25 (5d10) fire damage.