Leviathan, commonly referred to by his nickname Lex and also known as the Domain Spirit of the Sea and Deep Sea Guardian is a guardian spirit and the Domain Spirit of the Sea. He is a dual water and ice spirit and takes the form of a giant crustacean-like creature.
Lex is a giant crustacean-like creature with two giant claws and two smaller claws and a large tail. His body is dark blue and dark green and his claws are designed to look like heads, likely to compensate for his tiny head. His eyes glow red and markings on his body glow light blue. On his antenna are three glowing orbs, one of which he tore off his body to give to his lover, Plezira.
Lex is a very strong-willed creature and is not afraid to showcase his abilities and powers. He takes any insults to his lover seriously. Before losing his memories, he was a very rageful creature and took advantage of his powers over the ocean to wash away things he didn't consider important, putting him at odds with Atmos and Ankyla. At some point in his life, he lost his memory and washed up on Atlantis, where the kind Atlanteans cared for him. Lex's personality went under a drastic change during his amnesia as he transformed into a calm and caring individual, which was only strengthened when he met Plezira.
Lex is very in love with Plezira, so much in fact that he tore off a jewel from his own body to present to her as a gift in declaration of that love. Lex sees Nessie, an affectionate nickname he calls her by, as the very creature that turned his life around. He is very protective of her.
As the Domain Spirit of the Sea, Lex has control over the entire ocean as well as the liquid and solid forms of water. With the swish of his tail, he can generate powerful whirlpools and tidal waves to wash away his foes.
- Jewel Link: He is able to locate Plezira no matter where she is through the jewel he gave her and vice versa
- Blue Lightning: fires blue lightning from his claws at the opponent
- Claw Hammer: smashes foe with his claws
- Tsunami Tail: Lex whips his tail and creates a massive wave.
- 10 Eyes: an ancient attack that has only been used in dire situations. Those who miraculously survive the attack swear the last thing they see are ten glowing eyes.
- Dragon Wave: unleashes a wave of energy
- Flash Freeze: Leviathan unleashes a sudden ice attack that instantly freezes the opponent.
- Cascading Deluge: summons a downpour of rain that freezes into sharp icicles.
- Boiling Steam: spits boiling water from his mouth
- Torrent Cannon: unleashes a powerful jet of water from his claws and mouth
Leviathan is the Domain Spirit of the Sea and resides deep within the ocean. He did not care for the welfare of others and only cared about himself. He would often let his waters do whatever they wished, which put him in opposition with Atmos and Ankyla often as his neglection of his duties directly affected their domains, causing the three to fight often, creating chaos across the three domains of sky, land and sea.
At some point in his life, he struck his head and lost all his memories, forgetting he was a Domain Spirit and all his powers. He washed up on Atlantis where it's kind people nursed him back to health. Touched by their kindness, Leviathan vowed to protect the island, as he was in their debt. However, he was unable to save them when a massive tidal wave washed the island and it's people away and sank the civilization beneath the ocean's surface. As Lex did not remember who he was and what he could do, he could not stop the wave, though it is very likely that he accidentally caused it in the first place.
Consumed with grief, he lingered at the ruins of Atlantis, feeling guilty for failing to save it's people. He eventually met Plezira, who took him away from Atlantis, taught him to move on and showed him the rest of the world and what it had to offer, falling in love with her in the process.
- Lex's design is based on the Disney film, Atlantis: The Lost Empire
- Lex is based on the Leviathan.
- Lex is the only Domain Spirit whose name does not begin with 'A.'