Aquarius, Creator of the Sea

Water Form. Aquarius can enter a hostile creature's space and stop there. It can move through a space as narrow as 1 inch wide without squeezing.

Freeze. If Aquarius takes cold damage, it partially freezes; its speed is reduced by 20 feet until the end of its next turn.

Brute. A melee weapon deals one extra die of its damage when Aquarius hits with it (included in the attack)

Elemental Nature. A great water elemental doesn't require air, food, drink, or sleep.

Freedom of Movement. Aquarius ignores difficult terrain, and magical effects can't reduce its speed or cause it to be restrained. It can spend 5 feet of movement to escape from non magical restraints or being grappled.

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

Siege Monster. Aquarius does double damage on objects and structures.

Multiattack. Aquarius makes two slam attacks.

Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) bludgeoning damage.

Whelm (Recharge 4–6). Each creature in Aquarius's space must make a DC 15 Strength saving throw. On a failure, a target takes 13 (2d8 + 4) bludgeoning damage. If it is Large or smaller, it is also grappled (escape DC 14). Until this grapple ends, the target is restrained and unable to breathe unless it can breathe water. If the saving throw is successful, the target is pushed out of Aquarius's space.

Aquarius can grapple one Large creature or up to two Medium or smaller creatures at one time. At the start of each of Aquarius's turns, each target grappled by it takes 13 (2d8 + 4) bludgeoning damage. A creature within 5 feet of Aquarius can pull a creature or object out of it by taking an action to make a DC 14 Strength and succeeding.

Leadership (Recharges after a Short or Long Rest). For 1 minute, Aquarius can utter a special command or warning whenever a non hostile creature that it can see within 30 feet of it makes an attack roll or a saving throw. The creature can add a d4 to its roll provided it can hear and understand Aquarius. A creature can benefit from only one Leadership die at a time. This effect ends if Aquarius is Incapacitated.

Water Vortex: Target player must make a DC 18 Dexterity saving throw. if succeeds then player gets pushed 10-20 feet from original spot. if failed, target player takes 13 (2d10 +2) slashing damage.

Frightful Presence. Each creature of Aquarius's choice within 120 feet of the Aquarius and aware of it must succeed on a DC 20 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each turn, ending the effect on itself on a success. If a creature's saving throw is successful or the effects ends for it, the creature is immune to Aquarius's Frightful Presence for 24 hours.

Parry. Aquarius adds 3 to its AC against one melee attack that would hit it. To do so, Aquarius must see the attacker and be wielding a melee weapon.

Aquarius can take 3 legendary actions, choosing form the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Aquarius regains spent legendary actions at the start of its turn.

Detect. Aquarius makes a Wisdom (Perception) check.

Water whip. Aquarius makes a water whip. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 13 (2d8 + 4) slashing damage.

Control Water (Costs 2 Actions). Aquarius casts control water with the bludgeoning damage of the whirlpool and to objects is increased to 6d8 rather than 2d8 (spell save DC 21). Aquarius maintains concentration and has advantage on Constitution saving throws to maintain it.