Oathkeeper

Oathkeeper is the second act of Cyno's Story Quest, the Lupus Aureus Chapter. In order to unlock this quest line, the player needs a Story Key, must have completed Chapter III: Act V - Akasha Pulses, the Kalpa Flame Rises, and reached Adventure Rank 40.
During the events of the quest, the Traveler and Paimon help Cyno and his foster guardian with matters regarding a mysterious organization.
==List of Quests==
# The Mysterious Letter
# After Repose
# Footprints Sunken Beneath the Sands
# Sage of Sages
# The Dead Past is the Living Present
==Summary==
; The Mysterious Letter
Having been a while since they last caught up with their friends in Sumeru, Paimon suggests to the Traveler that they check in on how they're faring. They arrive at the Sumeru Akademiya, where they run into Cyno. Paimon explains that after seeing a large mushroom on the road, she was reminded of their friends in Sumeru. Cyno likewise returns the sentiment, as he and his friends were just discussing about them. He reveals that he is handling a case, and the two offer to accompany him, which he accepts.
Inside, they find an old man talking to another person, who Cyno reveals is Cyrus, a former Spantamad sage who taught him and Lisa. Cyno introduces the two to Cyrus, who's honored to meet them. He explains that a few days ago, someone sent him a threat letter demanding ten million Mora or his secret would be revealed. As there were no witnesses, they examine the letter, taking note of the unusual paper it was written on and a stain that was hastily wiped up. They deduce that the culprit must be someone young and strapped for cash, so they go to Aarav, where Cyno orders him to investigate all the cafes and cover the exits. 
Aarav leaves, and as Cyno remarks on the culprit's next move, he immediately brandishes his polearm at a student seemingly looking at some books, deducing them as the suspect. The student believes Cyno is lying, but Cyno sees through his claim due to his gesture and takes him away. Cyrus returns, remarking on how fast the situation was cleared when Cyno and Aarav return. The suspect, Urraca, is a sixteen year old third-year student who was underperforming and took tutoring classes to improve his grades, but developed a gambling addict that caused him to lose more Mora than usual. While at the tavern, he overheard people talking about Cyrus and an "old woman across the street" who Cyrus recognizes as Zaha Hadi, who is likewise surprised he doesn't know who she is. 
Cyrus offers to treat Cyno to a meal for resolving the case in record time and asks that he bring Tighnari along. Paimon is surprised to hear that he's in the city, and Cyno explains that his master, Naphis, had called him and Collei to the city to help out with a project. The three head to Lambad's Tavern, where Cyno, Tighnari and Collei catch up with them. As they talk over the food, Kaveh arrives, who had come to buy some wine and coffee beans. The newcomers are brought up to news regarding Urraca before Kaveh takes his leave. With the meal finished, Cyno asks the Traveler and Paimon if they would like to camp with him, Tighnari and Collei as a way of welcoming them back to Sumeru, which they accept.
----
; After Repose
The next day, the Traveler and Paimon head to Gandharva Ville, where they find that the three have already set up camp. As night falls, Kaveh and Alhaitham unexpectedly arrive, having come to look for them. After Kaveh had returned from Lambad's, he told Alhaitham about Cyrus. Kaveh sketched the pattern on the letter and showed it to Alhaitham, who recognized an ancient emblem on the letter as that from the Temple of Silence. Feeling that something was wrong, they went to look for them, running into Cyno first. Upon hearing the news, Cyno went straight for Cyrus' residence, while Tighnari asks Collei to inform the Corps of Thirty about the news as they make their way back to Sumeru City.
Upon arriving, they head to Cyrus' house, though the retiree had long left before they came. They ask Zaha about the incident, who remarked that Cyrus looked lost in thought. She then gives them a letter from Cyno, who tells them to not go after him. Tighnari suggests reconvening at the Akademiya, where they find Alhaitham and Kaveh. Alhaitham tells them the Temple's history with the Akademiya, and thus conclude that Cyrus must have went to the desert. Napis then arrives and informs them that the Corps of Thirty confirmed that both Cyrus and Cyno went west towards Caravan Ribat. As the situation involved the Temple of Silence and the Akademiya had a "shameful" history with them, Napis urges them to bring Cyrus and Cyno back safely.
----
; Footprints Sunken Beneath the Sands
Arriving at Caravan Ribat, the three catch up to Cyno, who was finishing up a conversation with Candace and Dehya. Despite his insistence that he could handle the situation alone, he eventually relents and allows them to accompany him. As they approach Aaru Village, Tighnari asks about his connection with the Temple of Silence. Cyno admits that he doesn't remember too much about it, but knew that his powers came from Hermanubis after several trials before Cyrus brought him to Sumeru City. They run into Fodil and ask him where Cyrus went; he is unsure of his location, but tells them that he was going to an oasis.
At Thamud Oasis, the four come upon a group of people relaxing. Tighnari offers to talk to them, seeing that Cyno's appearance and reputation could complicate matters. A young man recognizes Cyno and after learning of their motives, asks them to follow him. He brings up a massive entrance, revealing it to be the Temple of Silence as he takes them inside. He introduces himself as Sethos and had already known why they had come. Sethos sends someone to fetch for their leader and allows them to wait. The Traveler asks him a few questions regarding the Temple of Silence before checking in on Cyno and Tighnari.
The leader, Bamoun, eventually arrives and he orders Cyrus out. Bamoun claims that Cyrus had betrayed the organization and must pay the price for his treachery. He states that the Temple's influence was fading without Hermanubis to guide them, and he had come into possession of two Ba Fragments — shards of his power. Many people volunteered to be his vessels, but the fragments rejected them. He eventually learned of two suitable vessels; his adopted grandson Sethos, and another child whose parents agreed to exchange him for a small fortune — Cyno. Bamoun had intended for a three-phase plan regarding the children and the fragments; resonance, implantation, recovery and observation. While the two children were successful in resonating with the fragments, before the second plan could be implemented, the fragments began to glow in a bright light. Realizing that they would be lost if he did not act, Bamoun had one fragment implanted into each child, after which Cyrus ended the experiment, taking Cyno with him.
Bamoun states that Cyno's fragment should be returned and given to Sethos, which Cyno shoots down as dangerous. Tighnari then points out that if he refused to and they did not return Cyrus, they would be at an impasse and believes that they must be hiding something from them. Bamoun then recognizes Tighnari as a descendant of the Valuka Shuna before coughing severely, prompting Sethos to order attendants to take him away. Sethos states that if Cyrus had not left with Cyno, the experiment would have been a success. Not shackled to the past like his grandfather, Sethos allows the group to leave apart from Cyrus. Cyno refuses the terms and asks Sethos to give him a day to make up his own terms, which he agrees to.
----
; Sage of Sages
Some time passes as the group reconvenes. Cyno does not want to give up Hermanubis' power as he needs it to protect Sumeru before Tighnari points out that Alhaitham and Kaveh had told him about rules in the desert tribes that revolved around honor and nobility. Thus, they decide to confront the Temple with their own terms and look for Sethos, with Tighnari also wanting to check on Bamoun. A quick diagnosis reveals that Bamoun is heavily stressed and his old age means that he has a few days to live at most. Cyno tells Sethos his terms; a winner-take-all in a Rite of Duels, which Sethos is surprised by but accepts.
The following evening, the duel begins, with Duaenre refereeing the match. The Traveler faces a Grounded Geoshroom and Grounded Hydroshroom, while Tighnari faces two Primal Constructs, both prevailing over their opponents. In the final round, Cyno faces off against Sethos, with both young men drawing Hermanubis' powers in the first half of the duel. Cyno's greater skill puts him at an advantage over Sethos, surprising him with an spear that sends Sethos plummeting onto the arena floor. After recovering, Sethos charges at Cyno, who reacts to the attack by disabling Hermanubis' power and grabbing his staff to parry the attack. Seeing this, Sethos likewise stops using Hermanubis' power and grabs his own polearm. Ultimately, Cyno manages to land a powerful kick on Sethos, sending him flying across the floor before pointing his staff at him, and Sethos concedes.
With all three rounds won, Sethos relinquishes his fragment, which Cyno takes and absorbs, creating a massive display of light which captivates Bamoun, recognizing it as Hermanubis' return and passes away. 
----
; The Dead Past is the Living Present
After a brief funeral, Sethos tells them that per his grandfather's wishes, Cyno is now the leader of the Temple of Silence. However, due to his duties as the General Mahamatra and not knowing how the organization works, Cyno decides to appoint Sethos as his leader, as he felt that if it was not for the duel or if he had other intentions, Sethos would have claimed both fragments. Cyno then realizes Bamoun's intentions; by forcing the two to a duel, they would bring Hermanubis' might into one person, and the outcome would benefit the organization regardless, as Bamoun knew that his successor had to be freed from the shackles of the past. Sethos admits that it was what he and his grandfather had planned all along, and as gratitude, they would allow anyone he or Lesser Lord Kusanali deemed worthy to peruse the knowledge stored by the organization. Sethos then tells Tighnari that Bamoun had been delighted to see a descendant of the Valuka Shuna, explaining their relationship to Hermanubis. Tighnari is impressed as while he knew that he was named after his kind, he had never known the extent of their history with the Temple. Cyno tells Sethos that he would make a report for Kusanali and that he should expect an official Akademiya delegation to come soon, asking him to come to the rainforest so he could build some relationships and know the other side, which he agrees to.
Returning to the Akademiya, Napis scolds Cyrus for his recklessness. The group decides to give the two a wide berth and as they walk around to inform the others, they run into Collei and Faruzan. Faruzan is likewise upset that she was not involved in resolving the matter, and Tighnari decides it would be best not to argue with her. Cyno gives Collei a signal to play her ace-in-the-hole by distracting Faruzan into giving her a tour of the Akademiya, which Faruzan is delighted to hear and agrees to. Before they leave, Tighnari gives her the phrase "cup," as an indicator to meet up at Puspa Café. They finally find Alhaitham and Kaveh studying and tell them of the events, before Cyno offers to treat them to coffee.
Arriving at the cafe, Paimon recalls to the others how the duel went. Kaveh is impressed that despite winning, Cyno ceded position of leader to Sethos, which he found dignifying. After finishing up desert, the group disbands, while Cyno asks the Traveler to follow him to the Sanctuary of Surasthana. They continue climbing up the Divine Tree, where Cyno reveals that it is his "secret" base; a place where he could unwind and clear his head, where he was in a similar situation to Sethos. Suddenly, he spots Cyrus and jumps down to greet him, where they look and reminisce over photos of them when they were younger, taken by Lisa. Cyno suggests that they visit Lisa sometime, which Cyrus agrees to do next week, but realizes that his tomato-growing contest against Zaha is at the same time and decides to postpone it.
==Characters==
==Soundtracks==
==Other Languages==
==Change History==
es:El protector de la promesa
vi:Người Thủ Hộ Lời Thề