RenHeng

RenHeng is the slash ship between Blade and Dan Heng from the Honkai: Star Rail fandom.

Canon
Blade and Dan Heng have a shared history of which the details are unclear. Blade and Dan Heng were once friends. However, Dan Heng had committed some sort of crime, causing him to become a fugitive. Blade chases after him so that he may pay the price for what he did.

History
The relic set Passerby of Wandering Cloud explains bits of Blade's past with his former friend, who is described to have strong slender hands and wield a spear, indicating that this friend is Dan Heng. In the past, the two used to spar, share drinks, and gaze at the moon together. However, this friend stubbornly adhered to their plans, causing a "beloved" to become a monstrosity and for everyone to fall into an abyss of remorse. Blade and Dan Heng share a pair of bracers that have a telepathic connection. Once, Blade tried using the connection to sense Dan Heng, and thought about how his resentment toward Dan Heng won't last forever. "Pairs of objects are destined for an eventual reunion. The long years of grudges and hatred between them should be savored, like ice-cold aged liquor, one slow sip after another until the bottle of resentment is finally empty.

Would the wearer of the other bracer feel the same? The unnamed didn't want to know."

- Passerby's Roaming Dragon Bracer description

Blade went on to join the Stellaron Hunters. As they tended to his appearance, Blade look back on his memories in a haze and decided to give his bosom friend a jade flask he had made by hand, only to realize that he is no longer there. It is worth noting that this bosom friend may be different than the friend described in Passerby's Roaming Dragon Bracer, and thus may not be Dan Heng.

Before joining the Astral Express, Dan Heng evaded Blade by hopping on multiple IPC ships. Blade in turn would destroy spaceships in pursuit of him. Each time they fought, Dan Heng would pierce his spear through Blade's heart. This never killed him due to Blade's self-healing ability. "But he still can't shake off the man with the beastly eyes.

If others in his homeworld felt hatred toward him, then that man only has a killing intent toward him — even the spaceships he had traveled on were all annihilated. That man had died before him, but would reappear soon after."

- Dan Heng Character Story Part II

According to Welt, Dan Heng doesn't know what he's running from, that all he knows is that something is chasing him and he has to run. This suggests that he doesn't fully remember his past with Blade and what he did.

Trailblaze Missions
In the beginning of the Xianzhou storyline, Dan Heng has a nightmare. Blade, captured by Jing Yuan, claims that of five people, three must pay the price. In the nightmare, Blade then points his sword at Dan Heng with a smile, telling him that is he one of the three. Dan Heng wakes up with a start and misses the Astral Express's Navigation Meeting as he recovers from his shock. He is not present when a Stellaron Hunter, Kafka, interrupts the meeting. She requests the Astral Express crew to clear up the Stellaron in Xianzhou, mentioning that her companion Blade is in danger.

Dan Heng stays behind on the Express while the Trailblazer, March, and Welt go to the Xianzhou Luofu. He asks Himeko to play him the transmission of their conversation with Kafka. Dan Heng pauses on the moment Kafka projects an image of Blade. In distress, he proclaims that the Xianzhou is in danger. Himeko is able to infer that Blade is connected to the past he wants to escape, and Dan Heng is afraid that his burden has caught up to him and will drag down his friends. Himeko comforts him and encourages him to go down there.

Quotes
"This isn't the first time he's seen this man. This man had become his own inseparable shadow. No matter how many times he runs this man through with his spear, the man always comes back.

He can neither lose to this man, nor truly win. Though he wants to run away, there is nowhere to run."

- Nowhere to Run Lightcone description.

Behind the Scenes
"Surprisingly, he doesn't seem to be very interested in other people around him, but there is a person named "Dan Heng" to whom he seems to have very strong negative feelings."

- Shin-ichiro Miki (Blade's JP VA), translated

Fanon
RenHeng is one of Star Rail's most popular slash ships. It already has appeal for its enemies-to-lovers potential, which is made deeper once fans look into the significant lore connections the two have.

RenHeng currently has 23+ works on AO3, being the fourth most written ship in the Honkai: Star Rail tag. Their biggest rival ships are JingRen and CaeHeng.

Theories
Warning: This section contains spoilers from leaks.  Based on evidence from leaks, popular theories suggest that Dan Heng is a Vidyadhara dragon, an immortal dragon race that loses their memories once they reincarnate, which is why Dan Heng doesn't remember who he's running from. Dan Heng is also said to be the King of dragons, which has the power to breathe life. This could mean that Dan Heng was the one who granted Blade his immortality.

Fandom
FAN FICTION

Trivia

 * The "Ren" part of their ship name comes from Blade's name in Chinese, 刃 (rèn)
 * The official Honkai: Star Rail Twitter featured the two in a promotional tweet.
 * On the official launch trailer, Dan Heng stands in a pool of water, which shows the reflection of Blade.
 * Both were featured alongside other male characters in the Japanese magazine Anan. In an interview portion, Dan Heng is asked why he doesn't talk more. Dan Heng replies, "Compared to someone else also participating in this project, I talked much more." This is clearly referring to Blade, who stays silent for the entirety of his interview.