Mercphobia (メルクフォビア Merukufobia), also known as The Water Dragon God (水神竜 Suijinryū), is one of the Five Dragon Gods that inhabit the continent of Guiltina. After being defeated by Natsu empowered by the flames of Ignia, his Magic Power became obsolete, insisting he'll remain in his human form as a regular human.
Mercphobia’s appearance is similar to that of a sea serpent, with a scaly underside, large wings, and a long, pointed nose. He bears a tribal-like design on his face while maintaining his two horns. Mercphobia is enormous even for a dragon; being stated to be larger in size than the fire dragon, Igneel and being shown to dwarf the aforementioned dragon's son Ignia.
In his human form, Mercphobia appears as a young man with shoulder-length hair, two long horns, and a facial tattoo over his right eye. He dons a dark coat over a long shirt, accompanied by loose pants tucked into pirate boots. His accessories include a necklace with three circular ornaments and black gloves that only partially cover his palm.
Mercphobia is a calm dragon worshipped as a god by the people of Ermina, although he can easily become hostile towards those he views as enemies. Conversely, he is quite welcoming towards the town’s visitors or those who have earned his trust, visible by his hospitality towards Team Natsu upon their arrival. Mercphobia takes responsibility for the care and well-being of the citizens of Ermina, presiding over them as a benevolent ruler while also driving away any threats to himself or the town. He is particularly dedicated to his assistant, Karameel, who he states is his “reason for living.” Despite his kind-hearted nature, Mercphobia acknowledges his cruelty and violence as the Water Dragon, admitting that he previously thought of humans as comparable to ants. Because of this, he regards himself neither good or evil, although he openly supports coexistence with humanity.
Due to his growing frustrations about his powers’ threat to Ermina, Mercphobia constantly worries for the citizens’ safety and considers himself a danger to them. As such, he has become unafraid of death, even resorting to have Elefseria’s assassins to kill him in an attempt to sacrifice himself for their sake.
Mercphobia existed as far back as the Dragon King Festival, having killed numerous humans, some of which included Elefseria’s family. He along with the other Five Dragon Gods fled to Guiltina in order to escape Acnologia and became known later became known among that moniker of "gods". After some time, he rescued Karameel, a human who had been shipwrecked in his sea. From there, Mercphobia became a peaceful dragon who supported coexistence with humanity, ultimately coming to lead the people of Ermina Town, who worshipped him as a god. He later requested Carmille to locate Faris to remove his powers before they end up out of control, but she only removed the control of them, allowing her to manipulate his power at their behest.
100 Years Quest arc
Mercphobia witnesses Team Natsu entering Ermina as Karameel informs him that they are residents of the southern continent. Hearing the confrontation between Diabolos and Team Natsu, Mercphobia descends into the ocean, parting the seas and demanding that the two parties leave Ermina. However, the dragon eaters are suddenly teleported away by Black Ash, much to the Water Dragon’s surprise. He then inquires of the Fairy Tail mages’ objective, to which he learns that they have been sent by Elefseria, although with no intention of unnecessary violence. Mercphobia acknowledges their peaceful approach and invites the group to his palace, instructing Kashima to treat them as his guests.
At his palace, Mercphobia undoes Lucy’s transformation magic on Wendy, who had been turned to a jellyfish, and briefly introduces the group to Karameel. Amused by her ill-mannered response, Mercphobia requests that she leave before explaining his history with her to the mages. He also describes his past as the Water Dragon, admitting to having killed Elefseria’s family, although he assures the group that he now supports coexistence with humanity. Mercphobia then proceeds to showcase his numerous underwater facilities, managing to convince Team Natsu of his good will and merit through his dedication to the people of Ermina. However, he also confides in them his uncontrollable level of magic power, which he explains are the reason for town’s unnatural submersion at high tide. Believing that he poses a threat to the citizens’ safety, Mercphobia requests that the mages kill him to prevent a potential calamity, although not before he is able to correct a critical error.
Revealing that his powers have been stolen away by a person called the White Wizard, Mercphobia admits his fears of his magic being misused and firmly resolves to reclaim his powers. However, they are interrupted by the arrival of the Diabolos mages, who overhear Mercphobia’s confession and decide to steal his powers from the White Wizard themselves. Angered, the Water Dragon sends a wave towards the trio, but is quickly defeated by Skullion. Unable to fight, Mercphobia watches the Fairy Tail mages fend off the dragon eaters. However, he later shields Karameel from Kiria’s attack, and is heavily wounded as a result. After Team Natsu leaves to pursue the Diabolos mages, Mercphobia is tended to by Karameel in his palace. He later awakens, but suddenly grabs his assistant’s neck forcefully, yelling for her to flee.
As a result of Faris maximizing his magic power, Mercphobia reverts to his dragon form and proceeds to rampage through Ermina. In an attempt to stop him from harming the citizens, Mercphobia is attacked by Team Natsu with a barrage of dragon slayer magic, but he remains unscathed and lifts the sea above Ermina. Mercphobia sends a destructive water-based attack down on the harbor, and counters the Mages by neutralizing Natsu’s magic and dispelling Gray’s ice. The former manages to jump onto the Water Dragon, although Mercphobia continues to negate Natsu’s magic with ease. He creates a vortex from the sea overhead, which envelopes the dragon slayer; however, Ignia, the Fire Dragon God, lifts Natsu out of the vortex, refusing to hand him to Mercphobia.
Still under the influence of Faris, Mercphobia is unable to comprehend Ignia’s inquiries about his state of mind. As the latter utilizes his power to burn the harbor, Mercphobia brings rainfall down on Ermina in order to extinguish his fire. After Ignia departs from the battle, Mercphobia is suddenly ambushed by Natsu, who has been strengthened from consuming the flames of the Fire Dragon God. Mercphobia is thrown headfirst into the town structures by the dragon slayer, completely overwhelmed by his newfound power.
Magic and Abilities
Water Dragon Slayer Magic (水の滅竜魔法 Mizu no Metsuryū Mahō): Mercphobia can utilize Water Dragon Slayer Magic to a high degree, such as splitting the ocean, creating a barrier, even moving the sea into the sky, creating pillars of water, converting ice to water in an instant and creating a giant deadly whirlpool. He is also able to cover his body with water giving him immunity against Natsu Dragneel's Crimson Lotus: Exploding Flame Blade.
- Water Dragon's Roar (水竜の咆哮 Suiryū no Hōkō): Similar to other Dragons and Dragon Slayers, Mercphobia has shown the ability to use his element in the form of an attack coming from his mouth. This water based roar was able to completely overpower Natsu Dragneel's Fire Dragon King's Roar.
Transformation Magic (変身魔法 Henshin Mahō): Mercphobia, like the other Five Dragon Gods, is able to change appearances into that of a full-fledged human, and he can revert-back to his true dragon self whenever he wishes.
Animal Transformation: Mercphobia is capable of morphing humans into sea creatures, such as fishes, to allow them to adapt to untamed powers. He used this Magic to give the citizens of Ermina the ability to morph into sea creatures to allow them to continue to worship him as residents of Ermina. (Unnamed)
Flight: As a Dragon, Mercphobia possesses the ability to fly through the air using his wings.
Immense Durability: Mercphobia's durability is strong enough to take on the combined attacks of Team Natsu, most of which are enchanted with Dragon Slayer attributes and Natsu's Fire Dragon God induced Dragon Force. However, Mercphobia's durability did not play out for very long as his strength continuously dwindled due to his weakened state, which ultimately lead to his defeat.
Immense Magic Power: As one of the Five Dragon Gods, Mercphobia possesses an immense amount of Magic Power which is said to be equal to that of Acnologia. Mercphobia revealed that he was no longer able to control his Magic Power to the point of causing abnormal high tides that constantly submerges the Ermina Town and will eventually submerge more locations as time goes on. After Faris had stolen Mercphobia's power of restriction, his Magic Power went even more out of control to the point where when he released half of his power, it easily tore Ermina Town apart.
- (To Team Natsu): "Despite what I may seem like now, I killed many humans in the past. Like ants before the tide."
- (To Karameel): "The next time Elefseria’s Mages come here...I should probably sacrifice my own life."