DanCae

Dancae is the slash ship between Caelus and Dan Heng from the Honkai: Star Rail fandom.

Canon
After Kafka and Sliver Wolf seal the Stellaron inside the newly-activated receptacle Caelus’ body, they leave him, unconscious, on Herta Space Station. He is found later by March 7th and Dan Heng, the latter about to perform mouth-to-mouth CPR on Caelus’ prone body until March notices him waking up. After learning that he has no recollection of his past, apart from his name, the pair from the Astral Express, ‘a train that can travel between the stars with the power of the Trailblaze Aeon’, decide to let him tag along in heading to the master control zone, where the lead researcher of the space station, Asta, has gathered all the researchers, and also where the Astral Express is ‘parked’.

When Himeko asks if March’s been any trouble for Dan Heng and Caelus, by entering a specific dialogue option, (‘In that case, I'd rather not answer.’) March remarks that ‘we have two Dan Hengs on our team now’, showing that the two are relatively similar in some aspects.

In order to find Dan Heng after the three Astral Express members, as well as Bronya Rand, are brought to the Underworld by Sampo Koski, Caelus joins March in playing a game of hide-and-seek with the Moles, a group of friends in the Underworld who call themselves ‘an adventure squad’, to find his whereabouts. Upon finding out that he’s been dragged to the Fight Club by Sampo, the pair rush there immediately, finding him preparing for a fight against the ‘unfeeling, incendiary, explosive might of Team Robomatic’. After witnessing this, Caelus and March 7th jump into the fighting ring to help him.

Fanon
Their pairing is usually thought of with Dan Heng as the ‘dominant’ one in the relationship, though their positions are sometimes swapped. This ship is relatively popular, but admittedly not as well-known as RenHeng. It is also known as a ship between friends.

Fandom
Dan Heng/Caelus tag on AO3

Dan Heng & Caelus tag on AO3