Xi Ruo

Biodata

Feature	Details
Name	Xi Ruo (溪若)
Alias(es)	Mermaid King; King of the Sea; “Merman Brother”
Species/Race	Mermaid; Million-Year Spirit Beast 11 23
Gender	Male
Affiliation	Mu Yu (contract partner); sea Soul Beasts
Occupation/Role	Ruler of the mermaids and a deep-sea overlord
First Appearance	Chapter 2 — forms a contract with Mu Yu through the Mermaid’s Tear 2

Background / History

Xi Ruo formed a contract with Mu Yu when she activated the Mermaid’s Tear, agreeing to protect her when she faced danger. He subsequently resided in her Sea of Consciousness and could communicate with her through the necklace. 2 3 8

He initially aided Mu Yu discreetly, advising her during her first Soul Ring hunt and lending power while she absorbed a Ten Thousand Year Three-Eyed Golden Lion Soul Ring. Mu Yu kept his existence hidden, presenting the Mermaid’s Tear merely as a natural Soul Tool. 8 9

Xi Ruo openly appeared when Bibi Dong and Mu Yu were confronted by Xiao Wu’s mother, the Sky Azure Bull Python, and the Titan Giant Ape. Identifying himself as the Mermaid King, he intimidated the land Soul Beasts and declared that Mu Yu was under his protection. His reputation was such that even the Sea God was said to avoid provoking him. 11

During Mu Yu’s passage through the Hell Road, Xi Ruo protected her from the Dark Gold Three-Headed Bat King and personally killed the Ten Headed Fierce Yang Serpent, delivering its inner core to Mu Yu. 13

He later assisted Mu Yu throughout the Sea God’s Black-level trials, stimulating her cultivation with his Soul Power, helping her confront the Demonic Orca King, and providing a waterproof barrier during her absorption of its Soul Ring and Soul Bone. 18

Xi Ruo continued to serve as Mu Yu’s foremost sea-based ally, regulating her energy during Little Mo’s Spirit Soul contract, fighting the Deep Sea Demonic Whale King alongside her, and helping restrain Di Tian. 19 25 28

Appearance

Xi Ruo usually manifests as a mermaid with a human upper body and a fish tail. He can reduce himself to human size when requested by Mu Yu. 11 18

• Light-blue hair that coils around Mu Yu when he appears. 11
• Exquisite, handsome facial features. 11 13
• A large mermaid form when manifesting his full presence. 18
• Can wield a trident in battle. 13

Personality

Xi Ruo is proud, domineering, and fully aware of his overwhelming status among Soul Beasts. He openly states that strength gives him the right to act as he pleases, and he has little patience for land Soul Beasts that challenge him. 11

Around Mu Yu, he is markedly more playful and needy. He seeks her praise after helping her, becomes jealous when she calls another being useful, and is willing to carry out dangerous or inconvenient tasks for her. 13 18 36

He is intensely protective of Mu Yu, calling her his “little darling” and “child” when threatening those who endanger her. However, he also repeatedly misreads their bond as romantic, an assumption quickly rejected by Mu Yu’s guardians. 11 42

Abilities & Skills

Million-Year Soul Beast Power

Xi Ruo is a Million-Year Spirit Beast and one of the sea’s strongest known beings. His presence alone can force powerful Hundred-Thousand-Year Soul Beasts into submission. 11 23

• His aura immobilized or intimidated Xiao Wu’s mother, the Sky Azure Bull Python, and the Titan Giant Ape. 11
• The God of Space considers Xi Ruo an existence he cannot provoke lightly. 19
• He can contend with the Deep Sea Demonic Whale King, another Million-Year Spirit Beast. 25 26
• He assisted in restraining Di Tian after Mu Yu captured him. 28

Trident Combat

Xi Ruo can summon and fight with a trident, using it with decisive force against powerful Soul Beasts. 13

• Killed the Ten Headed Fierce Yang Serpent in roughly ten minutes. 13
• Retrieved the serpent’s inner core for Mu Yu after the battle. 13
• Fought the Deep Sea Demonic Whale King directly while Mu Yu provided support from range. 25 26

Sea of Consciousness Link

Through his contract with Mu Yu, Xi Ruo can appear in her Sea of Consciousness, communicate over distance, and perceive her thoughts. 8 13 18

• Warned Mu Yu of nearby threats, including the Sky Azure Bull Python. 8
• Heard Mu Yu’s internal thoughts and reacted to her private remarks. 13 18
• Helped regulate Mu Yu’s internal energy during Little Mo’s transformation into a Spirit Soul. 19
• Can be absent from the Sea of Consciousness, leaving Mu Yu unable to call on him immediately. 23

Cultivation and Defensive Support

Xi Ruo can provide direct support to Mu Yu rather than simply fighting in her place. 8 18

• His power assisted Mu Yu’s survival during her absorption of a Ten Thousand Year Soul Ring. 8
• Stimulated Mu Yu’s Soul Power to help her advance toward level forty, though the process caused her severe cold and strain. 18
• Created a waterproof barrier for Mu Yu while she absorbed the Demonic Orca King’s Soul Ring and Soul Bone. 18
• Located the Ice and Fire Yin Yang Well by identifying the area of Sunset Forest with unusually few Soul Beasts. 22

Transformation and Sea Travel

Xi Ruo can alter the size of his mermaid form and command nearby sea Soul Beasts. 18

• Shrunk to a human-sized mermaid form at Mu Yu’s command. 18
• Provided Mu Yu with sea Soul Beast mounts when traveling around Sea God Island. 18
• Cannot walk comfortably in his fish-tailed form and instead rides on Mu Yu’s puppet when on land. 13

Equipment / Weapons / Items

• Trident — A trident Xi Ruo summoned to kill the Ten Headed Fierce Yang Serpent. 13
• Mermaid’s Tear — Mu Yu’s necklace and the medium through which their contract was formed and Xi Ruo can manifest. 2 9 11

Relationships

• Mu Yu — Contract partner and the person Xi Ruo is most protective of; he assists her cultivation, combats her enemies, and frequently seeks her approval. 2 11 18 25
• God of Space — A powerful deity who socializes with Xi Ruo; Xi Ruo is considered strong enough that the God of Space avoids provoking him. 19 25
• Sea God — The Sea God is stated to avoid provoking Xi Ruo despite being a First-level God. 11
• Deep Sea Demonic Whale King — Fellow sea overlord and frequent opponent; they have fought many times, later joining forces under Mu Yu’s command. 25 26
• Di Tian — Helped guard the captured Beast King while Mu Yu sought an audience with the Silver Dragon King. 28
• Ah Yin — Ordered by Mu Yu to retrieve Ah Yin’s Soul Bone from Tang Hao’s possession. 36

Story Role / Major Arcs

• Mermaid’s Tear Contract — Becomes Mu Yu’s contracted protector after the Mermaid’s Tear is activated. 2
• Star Dou Great Forest — Advises Mu Yu during her hunt for the Three-Eyed Golden Lion and aids her dangerous Soul Ring absorption. 8
• Bibi Dong’s Crisis — Reveals himself as the Mermaid King to protect Mu Yu and Bibi Dong from powerful land Soul Beasts. 11
• Hell Road — Clears Mu Yu’s path by killing the Ten Headed Fierce Yang Serpent and securing its inner core. 13
• Sea God’s Trials — Accelerates Mu Yu’s cultivation and supports her acquisition of the Demonic Orca King’s Soul Ring and Soul Bone. 18
• Deep Sea Demonic Whale King — Battles the Whale King so Mu Yu can complete her Sea God trial and later gain him as a Spirit Soul. 25 26
• Silver Dragon King Search — Serves as one of Mu Yu’s guards while she takes Di Tian hostage to force a meeting with the Silver Dragon King. 28
• Ah Yin’s Resurrection — Takes on Mu Yu’s request to steal Ah Yin’s Soul Bone. 36

Notable Quotes

“Simply because this King’s strength is superior to yours, this King will do as he pleases.” 11

“Remember, I am useful to everyone!” 13

Trivia

• Mu Yu initially referred to Xi Ruo as her “Mermaid brother” when explaining the Mermaid’s Tear to Qian Daoliu. 3
• Xi Ruo becomes visibly jealous when Mu Yu praises the usefulness of another being or item. 13
• Mu Yu once introduced Xi Ruo to Qian Daoliu as unimportant compared with her other Spirit Souls. 29
• In a later side story, Xi Ruo mistakes Mu Yu taking him alone to the Douluo Continent as proof that she reciprocates his feelings. 42