- Unukalhai was born on the thirteenth reflection of Hydaelyn, the world that became known as the Void. Despite being gifted with the Echo, he was barely more than a child when the world ended, and was unable to stop the Flood of Darkness from transforming his world. Unukalhai was rescued by Elidibus, the Emissary of the Ascians, who explained the importance of maintaining the balance between light and darkness. Unukalhai continued to serve as Elidibus's disciple, swearing to never allow what happened to his world happen to any other.
- 蛇心诞生于海德林的第十三个镜像世界中，这个世界已经变成了虚无界[译注 1]。尽管被赐予了超越之力[译注 2]的天赋，当这个世界终结时，他终究还是个孩子，无法阻止暗之泛滥在他的世界中传播。蛇心被白袍无影·调停者艾里迪布斯救了下来，并向他解释了维持光与暗均衡的重要性。蛇心继续作为门徒服侍着艾里迪布斯，发誓不会允许这种事情再在其他世界发生。
- After the defeat of Thordan VII the Warrior of Light is told that a visitor is waiting for them in the Scions' headquarters, the Rising Stones. They find a young, masked man who introduces himself as Unukalhai. He claims to have been sent by his master to aid the Scions of the Seventh Dawn in facing the coming threat of the "eikons", primals that were summoned during the Third Astral Era. Known as the Warring Triad, they were defeated and imprisoned by the Allagan Empire, and sealed on the floating island of Azys Lla. The actions of Archbishop Thordan VII, who tried to gain their power for himself, has weakened their seals, making it possible for them to break free—a process the Garlean Empire may hasten in their attempts to uncover the secret of binding primals. This explanation is corroborated by Urianger.
- 在光之战士击败托尔丹七世后，被告知有一位来访者在拂晓的总部石之家[译注 3]等待着他。光之战士会发现一名自称蛇心的蒙面男子。他宣称被他的主人送来协助面临“荒神”[译注 4]的威胁的拂晓。荒神是在第三星历期间被召唤的。他们被称作三斗神[译注 5]，被亚拉戈帝国击败并监禁，还被封印在魔大陆阿济兹拉的浮空岛中。教皇托尔丹七世尝试获取他们力量的行为，削弱了他们的封印，使他们有机会重获自由——这也许会让加雷马帝国加速解开蛮神身上秘密的进程。该解释被于里昂热证实。
- Before the Triad can be dealt with, the Warrior of Light is told to defeat the primals Bismarck and Ravana, who have been resummoned by their respective worshipers. Unukalhai wants to assist, offering instruction on how to confront them, including two enigmatic gems associated with each primal.
- When it comes time to deal with the Warring Triad directly, Unukalhai instructs the Warrior of Light to journey to Azys Lla alongside Krile, Urianger and Y'shtola Rhul. He leads them to Containment Bay S1T7 where Sephirot, the first of the Triad to risk being awakened, is held. While Y'shtola and Urianger distract the Garlean forces patrolling the area, the Warrior of Light, Unukalhai, and Krile unseal and defeat Sephirot within its containment.
- 当直面三斗神之日来临时，蛇心在光之战士与可露儿、于里昂热和雅·修特拉前往魔大陆阿济兹拉的旅途中，指引他们前往抑制绝境S1T7[译注 6]，三斗神其一萨菲洛特，在那里有觉醒的风险。当雅·修特拉与于里昂热去分散在这个区域巡逻的帝国军注意力时，光之战士、蛇心和可露儿在这个设施中解开萨菲洛特的封印，并将其击败。
- While leaving the area, Unukalhai is approached by Regula van Hydrus. Unukalhai criticizes the Garleans' attempts to control the power of the primals. Regula rebuffs this lecture, but leaves without a fight. Krile attempts to question Unukalhai's motives and background, and though he shows a brief flicker of emotion, he quells it without revealing anything of his past.
- After returning to the Rising Stones, Unukalhai reveals more of the background of Sephirot, and offers the Warrior of Light an Allagan Tomestone that will allow them to enter a combat simulation pitting them against a stronger version of the eikon.
- Unukalhai brings word to the Warrior that Regula van Hydrus has broken the wards that Urianger used to seal off the Aetherochemical Research Facility. Conferring with the Scions, Unukalhai believes van Hydrus is after the "Genesis Expression", one of the most powerful pieces of Allagan technology, and recommends pursuing and, if possible, slaying him. The Warrior of Light, Unukalhai, Urianger, Y'shtola, and Krile venture into the facility, fighting off waves of Garlean troops. Krile is injured, and Unukalhai stays behind to protect her, earning her trust and gratitude. Although the Warrior of Light defeats van Hydrus and prevents him from retrieving the Allagan tomelith, he escapes.
- 蛇心给光之战士带来消息，雷古拉·范·休著斯已经打破于里昂热用来封锁魔科学研究所[译注 7]的守卫。蛇心在与拂晓商议时，确信雷古拉·范·休著斯的目标是“变换式”[译注 8]，这是亚拉戈科技中最重要的一部分。他还建议去跟着雷古拉·范·休著斯，如果存在可能的话，杀掉他。光之战士、蛇心、于里昂热、雅·修特拉与可露儿冒险进入研究所，击退了数波帝国军队。可露儿受伤后，蛇心留下来保护她，赢得了她的信任与感激。尽管管光之战士击败了雷古拉·范·休著斯并成功阻止其获取亚拉戈的技术，但还是被他逃走了。
- Urianger asks to speak to the Warrior of Light and Unukalhai in private, revealing that he deduced it was Unukalhai who broke the seal on the facility, hoping to lure Regula van Hydrus into a trap where he could be killed. Unukalhai admits this to be the case and Urianger chides him, claiming that had he trusted the Scions enough to tell them his plan, it may have succeeded. Urianger asks the Warrior of Light to forgive Unukalhai and to conceal it from the other Scions.
- To atone for his lack of honesty, Unukalhai shares some of his personal history with the Warrior of Light, and reveals that he, too, possesses a form of the Echo. He hails from a conflict-ridden land where he learned magic to survive until his master recruited him. He tells the story of another world where people believed they could harness the power of primals using Auracite leading to the destruction of their world. The fear of it happening to Eorzea causes him to despise van Hydrus and the Garlean Empire.
- 为了对自己缺乏诚信的行为进行弥补，蛇心对光之战士分享了一些他的个人历史，透露他也拥有一种超越之力。他来自一片充斥着纷争的土地，在那里他为了求生而去学习魔法，直到他的主人将其招入麾下。他讲述了有关另一个世界的故事，那里的人们由于相信他们能通过使用圣石[译注 9]来驾驭蛮神的力量，最终导致他们的世界走向毁灭。出于对此类事件在艾欧泽亚发生的恐惧，他蔑视着雷古拉·范·休著斯与帝国。
- The second of the Warring Triad, the goddess known as Sophia, is about to awaken. The Warrior of Light again travels to Azys Lla with Urianger, Y'shtola and Krile, and they find several of Sophia's thralls who had been sealed alongside her by the Allagans. While Urianger and Y'shtola deal with the thralls, Unukalhai, Krile and the Warrior enter Containment Bay P1T6, and defeat Sophia.
- 三斗神其二索菲娅即将醒来。光之战士与于里昂热、雅·修特拉和可露儿再次前往魔大陆阿济兹拉，发现了几名被亚拉戈人封印在索菲娅身边的信徒。当于里昂热和雅·修特拉处理处理这些信徒时，蛇心、可露儿与光之战士进入了抑制绝境P1T6[译注 10]，并击败了索菲娅。
- While the Scions prepare to leave, Unukalhai stays behind to shut off the life support for Sophia's remaining thralls to prevent another summoning. When later asked about his actions, he explains he knew it had to be done, but did not want the Warrior of Light to have to sully themselves with such a distasteful task. Y'shtola explains that all of the Scions, including the Warrior, know what has to be done in the battle against the primals, and are willing to do what is necessary, including the slaying of thralls. Unukalhai admits that he had been mentally placing the Warrior of Light on a pedestal, seeing them more as the embodiment of an ideal than as an individual, and promises to not underestimate their resolve in the future. He presents the Warrior of Light with a Tomestone containing data on Sophia, allowing them to challenge a simulation of a stronger version of the goddess.
- When it comes time to confront Zurvan, the final member of the Warring Triad, Unukalhai again journeys to Azys Lla with the Warrior of Light, Urianger, Y'shtola, and Krile. They are confronted by Regula van Hydrus, who, to their surprise, offers them an alliance. Having decided that the Allagan method of containing primals was flawed, and thus useless to the Empire, he wishes to destroy Zurvan and his thralls. The Scions reluctantly agree to the alliance, and travel to Containment Bay Z1T9 where Regula's troops are already fighting Zurvan's thralls. Unukalhai is defeated and nearly slain, but is saved by Regula, who takes a mortal blow from Zurvan. When he asks the dying Regula why he saved him, Regula states that Unukalhai's powers are better suited than his to end the primal threat.
- 当与三斗神的最后一名成员祖尔宛的对峙之日来临时，蛇心再次与光之战士、于里昂热、雅·修特拉和可露儿前往魔大陆。他们撞见了雷古拉·范·休著斯，出乎他们意料的是，他向他们提议结盟。由于帝国方面已经判定亚拉戈包含蛮神的方法有缺陷，对他们没用，他决定去摧毁祖尔宛和他的信徒们。拂晓勉强同意了结盟，在前往抑制绝境Z1T9[译注 11]时，雷古拉的军队已经在与祖尔宛战斗了。蛇心被击败，快要被杀死时，却被雷古拉替他承受了祖尔宛的致命一击而将其救了下来。当蛇心询问垂死的雷古拉，他为何要救自己时，雷古拉说蛇心的力量比他更适合终结蛮神的威胁。
- After Zurvan's defeat, Unukalhai, ashamed of his self-perceived weakness compared to the Scions, asks them to meet him back at the Rising Stones where he unmasks and reveals his past. The Scions, after learning that he faced the end of his world alone, tell Unukalhai that he no longer has to fight by himself, and welcome him as a member of the Scions of the Seventh Dawn. Despite the newfound friendships he has forged, Unukalhai insists on putting his mask back on. He presents the Warrior of Light with a Tomestone containing data on Zurvan, allowing them to challenge the final, and most difficult, simulation battle.
- Unukalhai is the traditional name of Alpha Serpentis, the brightest star in Serpens, a constellation often represented as being held by Ophiuchus. As Ophiuchus is the symbol associated with Elidibus, this likely hints to a connection to the Final Fantasy XIV character of the same name.
- Unukalhai是巨蛇座 α（Alpha Serpentis）的传统名称，它是巨蛇座 （Serpens）内最亮的一颗星。巨蛇座通常以被蛇夫座（Ophiuchus）所掌控，作为其代表性形象。由于蛇夫座是与艾里迪布斯有关联的符号，这一点可能也暗示着Unukalhai（巨蛇座 α ）这颗星与FF14中跟它同名的人物Unukalhai（蛇心）之间的联系[译注 12]。
- 虚无界：the Void
- 超越之力：the Echo
- 石之家：the Rising Stones
- 荒神：the eikons
- 三斗神：the Warring Triad
- 抑制绝境S1T7： Containment Bay S1T7
- 魔科学研究所：the Aetherochemical Research Facility
- 变换式：Genesis Expression
- 抑制绝境P1T6：Containment Bay P1T6
- 抑制绝境Z1T9：Containment Bay Z1T9
- Unukalhai，源自阿拉伯文的 عنق الحية；unuq al-ħayyah、"neck of the snake"，和由拉丁文翻译的Cor Serpentis：“蛇的心脏”，中文将该人物翻成“蛇心”，正好可以看出这层关联