KaeLuc

"Hahaha... Who knows, perhaps we're fated to be doomed together. Right, Master Diluc?"

- Kaeya, Midsummer Island Adventure Event

KaeLuc is the slash ship between Kaeya Alberich and Diluc Ragnvindr from the Genshin Impact fandom.

Canon
Kaeya and Diluc first met as children, when Kaeya was abandoned outside of Dawn Winery by his birth father and taken in by Diluc’s father Crepus. We don’t know how old they were when Kaeya was abandoned, but he must have been at least 11 or 12 to understand the importance of his mission. The two became friends and saw each other as sworn brothers, and were extremely close in their teens. They were well known throughout Mondstadt and were so in sync that many thought they were like twins.

On the night of Diluc’s 18th birthday, he and his father were attacked while traveling home to the Winery. Diluc’s father was critically injured while defending Diluc, and it is implied in the webtoon that he had to kill Crepus himself to end his father’s suffering. Kaeya arrived too late to save Crepus.

That night, Kaeya revealed his true identity to Diluc — he was a secret agent from Khaenri’ah, who was planted in Mondstadt, as “last hope.” This led to a life or death confrontation between the two which ended with Kaeya receiving his Vision.

Soon after this, Diluc abandoned his Vision and left Mondstadt for three years.

The events of Diluc’s return to Mondstadt are unclear, but Diluc and Kaeya began working together again soon after, trapping a Fatui diplomat in the Winery’s cellar to interrogate him and sharing intel throughout the events of the webcomic. The two work together to resolve the Black Fire Incident, staging fights against each other and and purposefully getting Diluc captured.

At the end of the webcomic, Kaeya returns Diluc’s vision to him inside of a large ornamental vase. After this, Diluc takes up his vision once again. Despite claiming that he has no recollection of the vase, Diluc keeps it on display in the winery.

During The Darknight Hero’s Alibi, Kaeya purposefully sets up a situation involving Diluc and another Knight, Huffman, seemingly just to see how Diluc would react. Kaeya watches the show unfold and then tells Diluc that he’s happy that the latter now has an assistant when Diluc relies on the Traveler during the ensuing confrontation.

Kaeya and Diluc are also seen together in various other quests in the game, during which they typically exchange jabs at each other. During the Windblume event, despite snapping at each other, they also seem to have a short but normal conversation about how to improve business at Diluc’s tavern. They seem to have a confrontational relationship but are seen interacting often. Kaeya often attempts to provoke Diluc into sharing his true feelings or giving him a reaction, and Diluc in turn usually gives Kaeya a blank or emotionless reply. Diluc is highly critical of the Knights of Favonius, including Kaeya. The two both have extensive information networks within the city,

In the original Chinese text, Kaeya used to call Diluc "sworn older brother" (义兄 yì xiōng in Chinese), meanwhile Diluc refers Kaeya as "sworn younger brother" (义弟 yì dì in Chinese)  ''. Crepus refers to Kaeya as a "sworn son" (义子 yì zǐ in Chinese) in Kaeya's character story.

Voicelines
"Kaeya? You can only trust half of what he says... at best."

- Diluc's voice line about Kaeya

"You want to know what's in my glass? It's... grape juice. My drink of choice."

- Diluc's voice line about favorite food

"Diluc? He was cute as a young lad. But nowadays he just seems to be in a world of his own... Overall, not much fun to hang out with."

- Kaeya's voiceline about Diluc

"I don't like alcohol. It's just... I don't like how it feels in my mouth..."

- Diluc's voice line about least favorite food

"I can't believe that some people actually drink grape juice... if they had a little more patience, they would find that it ferments into the most exquisite wine. Hmph. So unromantic."

- Kaeya's voice line about least favorite food, mocking Diluc

Character Story Profile
"The other was the eccentric Kaeya. He was Diluc's friend, supporter, and sounding board, ensuring he got through every challenge he faced smoothly. They were almost like twins, knowing each other's thoughts and intentions without a word, protecting Mondstadt in both light and dark."

- Kaeya's Character Profile in Story 5

"Kaeya was Diluc's brother by adoption and was always by his side, but on this occasion, Kaeya did not partake in the final moments shared between father and son."

- Kaeya's Character Story Profile in Vision

"Since that day, Kaeya and Diluc have gone their separate ways. But he never discusses it, just as he never discusses the origin of his Vision."

- Kaeya's Character Story Profile in Vision

Story Quests
"Of course, we also have Master Diluc to thank the venue. Otherwise, we would be looking at quite an alarming bill right about now."

- Leo Minor, Jean's Story Quest

Manga
"May the Wind be with you, sir Kaeya."

- Diluc to Kaeya in both, Flame Born: Part 1 and Part 2

"You seem pretty cool despite all that crazy stuff happening out there, Diluc. You know what I am talking about."

- Kaeya to Diluc in Flame Born: Part 2

"Sir Kaeya... Saving Mond is your job. Try to do it properly next time."

- Diluc to Kaeya in Flame Born: Part 2

Midsummer Island Adventure
"I'll get to that. But first, I want to enjoy some of this island sunshine. Master Diluc might actually get a tan."

- Kaeya

"Anyone else find it hard not to crack a smile when Master Diluc says "Dodo-King"?"

- Kaeya

"And as for Kaeya... Hmph, he seems to be in high spirits. Even after all these years, he still enjoys summer as much as he did as a kid."

- When the player talks to Diluc and choosing the "About what happened today..." option.

"What's the matter? Diluc's scowl still bothering you? He's has that expression on his face for years now. He internalizes a lot of his feelings. So I'm afraid that his face is stuck like that. Just treat him like a big kid."

- When the player talks to Kaeya and choosing the "About what happened today..." option.

Fanon
This ship is the second most popular slash ship after ZhongChi. The ship receives lots of direct conflict with its shippers and those who don't ship Kaeluc due to the common argument between adoptive brothers and sworn brothers. In the original Chinese text, Kaeya and Diluc are referred to as Sworn Brothers (which is a very popular boy love trope in China), which often tends to describe men who are not related by birth, but who swore loyalty to each other; in the English translation however, Kaeya and Diluc are explicitly depicted as brothers, the lack of blood relation isn't a factor against this.

Those opposed argued that Kaeya and Diluc are German and there is no excuse to use the trope, 'sworn brothers' although Germany has well as history with the term sworn brothers (called blutsbrüder in German), being very similar to China. As well stated by MiHoYo that the game will contain popular tropes and small bits of Chinese culture. It is the most written ship for both Kaeya and Diluc on AO3. Kaeluc currently rivals Jeanluc which is Diluc's second most popular ship.

Media
Various official MiHoYo pages often publish art of two drinking at Diluc's bar, most notably Lantern Rite art published by Japanese account on February 14th, 2021 (tweet text suggests Diluc is busy, so he asks Kaeya to go home after he finishes the wine he gave him), which was headcanoned by many of the ship's fans as confirmation of the canonicity of their relationship, or at least bold support of the ship. While this makes sense in context, since the aforementioned Lantern Rite festival takes place in the second half of February, MiHoYo couldn't help but understand what impression does the published on February 14, Valentine's Day, illustration with two characters could make.

Fandom
FAN FICTION

TUMBLR

TWITTER

PIXIV

Trivia

 * The Twitter account of one of the illustrators of the official Genshin manga is almost entirely devoted to posting and reposting art with this ship.
 * Emojis like '❄️🔥' are used to reference the ship. With Kaeya being a Cryo user and Diluc a Pyro user. Another form fans use to reference the ship is using '🦚🦉' emojis as it refers to their constellation.
 * MiHoYo has retweeted KaeLuc fan art on their twitter account before.
 * In "Genshin Impact EP - At the Light of Dawn", Diluc is seen leaving Dawn Winery at night and returning at dawn. On the other hand, in "Klee and Kaeya's Mondstadt Tourist Information", a video available in the Japanese Genshin Youtube account and Bilibili, Kaeya enters Dawn Winery at night and leaves at dawn.
 * In the same tour video, Kaeya describes Diluc as "In many ways, a flawless gentleman". (いろんな意味であいつは完全無欠の紳士だよ)
 * In all the voiceovers except English, Adelinde's voiceline translates to "*sigh* When will Master Diluc finally make up with Young Master Kaeya?".
 * Both Kaeya and Diluc give 5 Apple Ciders in their birthday mails.
 * Kaeya is referred to as Diluc's "brain" (头脑) instead of "sounding board" in the Chinese version.
 * When Kaeya tries to convince Diluc into adding starters and mains in his tavern's menu during the Windblume Festival, he tells Diluc that "his mouth feels a little lonely" (嘴里有点寂寞呀) in the original and other translations.
 * In the Midsummer event, Albedo abandons Diluc and Kaeya saying the two could do with some alone time. Later in the quest, Albedo states that it was a personal choice and prefers to talk to intelligent people like the traveler, implying that he doesn't think the uncrowned king of Mondstadt or the esteemed cavalry captain are smart or at the very least when put together.
 * When Kaeya argues that he would be asleep on one of the other islands had Diluc possessed a Geo vision instead of a Pyro one, he uses singular pronouns in the original and majority of translations. However, in the Japanese Translation, Kaeya uses the pronoun "we" (俺たち), translating into "If you had a Geo vision, we would be asleep on one of the other islands".
 * Aether can be seen reading a book with a Pyro Abyss Mage and Cryo Abyss Mage on the cover with hearts around him in the merch that is exclusive to the GENSHIN★FES 2021.
 * Diluc has two versions of his Japanese Character Miscellany, one narrated by Tsuda Kenjiro (Dainsleif's JP VA) and the other narrated by Toriumi Kousuke (Kaeya's JP VA), being the only character to get this treatment so far.
 * During their cast interview, Kaeya and Diluc's Japanese VAs answered each other's character when asked about characters that caught their interest.
 * Ono Kensho (Diluc's VA) states that Kaeya definitely seems interesting from Diluc's perspective.
 * Toriumi Kousuke (Kaeya's VA) says he is given more instructions from the directors and that they pay attention to detail when recording scenes with Kaeya and Diluc, which is why he is keen to see how their story develops.

Variations

 * DCKZ refers to the two, Tartaglia and Zhongli