Diluk and Keya!

It would be a mistake to think that there's anything resentful about this relationship. Diluc, after the trials he's endured, has trust issues. He's deeply resentful of his adoptive brother and would like to change things, but he can't. Considering how much Kaeya meant to him in the past, one can imagine how much he's suffering now. He's not overtly hostile, but he's downright reserved in his interactions. His weapons are sarcasm and skepticism.

Kaeya, however, doesn't actively try to get closer, but he's always nearby and always ready. He displays friendliness and understanding. He likely knows that time is the only thing that can heal Diluc's emotional wounds, so he lets him grieve, mourn, be angry, and resentful. Regardless of Kaeya's feelings toward his fathers, he genuinely loves Diluc and worries about him.

The prospects for a relationship between these two remain bright. The more they interact and interact, the faster Diluc's heart will thaw. Perhaps the adoptive brothers will be able to reunite before the end of Genshin Impact. At least, we sincerely hope so.

These two are very different and complement each other perfectly. It's a shame they can't please us with a reconciliation right now.

Diluc takes on the guise of the Midnight Hero at night, protecting the city from threats. Kaeya discovered this sometime later, even after following Diluc and learning his secret. It seems he simply wanted to have fun and pull the wool over the gloomy Diluc's eyes. Nevertheless, in the final dialogue, Kaeya is glad his brother has found a helper. He's apparently worried about Diluc's extreme aloofness.

Kaeya and Diluc didn't just grow up together; they were, up until a certain point, inseparable. As can be seen from their character histories, Kaeya served as the leader, the "brains" of their tandem, and Diluc followed him wherever he went. Both brothers enlisted in the Ordo Favonius of Mondstadt, but the tragic death of Crepus Ragnvindr shattered their seemingly unshakable alliance.

Kaeya hails from the fallen kingdom of Kaenri'ah. He belongs to the influential Alberich clan, which assumed the regency when the one-eyed King Irmin lost his powers. His character's backstory reveals that he arrived in Mondstadt as a child. His father abandoned him at the Dawn Distillery, entrusting him with an important espionage mission. The distillery's then owner, Crepus Ragnvindr, adopted the boy into his family and raised him alongside his son, Diluc.

Diluc is the heir to the influential Ragnvindr clan. His distant ancestor participated in the rebellion against Archon Decarabian. The Ragnvindrs' seat is the Dawn distillery, the main wine producer in Mondstadt. Dawn wines are popular throughout Teyvat, making Diluc not only a handsome but also a wealthy young man.

Crepus was once traveling in a caravan from the Snowlands to Mondstat. He found a child along the way and took him in. It was Kaeya, who thereafter began to live with Crepus as a stepfather and Diluc as a new sworn brother. They were inseparable and got along well until their teenage years. They even began serving together in the Ordo Favonius, defending Mondstat. But one day... Diluc and Crepus were in the caravan when a dragon attacked. Ultimately, reinforcements didn't arrive in time, and Crepus was killed by the dragon. But only after his death did Kaeya arrive, having been too late to save his stepfather. Diluc was the only survivor. Diluc was angry at Kaeya for revealing his past. After Crepus's death, Kaeya, who had been raised in the Ragnvindr family as a brother, finally told Diluc the truth about his origins. For a long time, Kaeya hid the fact that he had been abandoned at the Dawn Distillery as a child, and that Crepus had later adopted him into the family. Diluc took this secrecy as a personal betrayal—at a time when he was already deeply traumatized by the loss of his father, Kaeya added the burden of other people's secrets. Then the brothers clashed in a duel, in which Diluc slashed Kaeya's eye, subsequently causing him to lose his right eye. Both gained god's eyes that day. Diluc received the pipo god's eye, and Kaeya the cryo god's eye. But then Diluc severed ties with the Ordo Favonius and Kaeya, who had covered up Crepus's death on orders. Diluc then went to Fatui himself to investigate his father's murder. But he later returned and took over the Distillery and worked as a bartender at his establishment, the Angel's Share tavern. Due to personal trauma, Diluc developed anger and detachment from Kaeya, mistaking his past with him for betrayal and lies. Kaeya merely continued to serve in the Ordo Favonius, wearing a mask of justice so that no one would see his pain from the past and the feelings he no longer wished to acknowledge. Although Kaeya still frequents Diluc's tavern and drinks wine there, occasionally even exchanging phrases and jokes, sometimes barely hinting at the brotherly bond between them in his words...