Xiefan is the slash ship between Xie Bi'an (White Guard) and Fan Wujiu (Black Guard) from Identity V.
Xiefan = Top Bi'an/White Guard & Bottom Wujiu (Black Guard)
NOTE: THRY ARE NOT BIOLOGICAL BROTHERS/TWINS, Shipping them is 100% okay.
If you want to know their backstory:
Fan Wujiu is a straightforward and stubborn person, while Xie Bi'an is humble and soft, with a loyal heart.
The two men have been friends since childhood and are like brothers.
One day when they were walking together to Nantai Bridge, it was about to rain, so Xie Bi'an asked Fan Wujiu to stay under the bridge while he went home to get an umbrella. After Xie Bi'an left, the rain begins to pour down the river rose. Fan is reluctant to leave the bottom of the bridge to keep his promise with Xie, so he stayed there. Soon Xie returned to Nantai Bridge with his umbrella, only to see that the river was over the bridge, and Fan Wujiu had drowned. Xie Bi'an was so distraught that he wore only white clothes from then on, carrying the black umbrella in rain or shine, and looked so mad that he finally died under the Nantai Bridge, leaving behind the black umbrella that witnessed his life and death.
The umbrella was bought by a merchant shortly afterwards.
The merchant placed the umbrella in the hall. After placing it in his house, he soon finds his house full of the sounds of men sighing and crying as he hears walking around at night. People believed that Xie Bi’an (White) resided in the umbrella, so the merchant hired a Taoist to do something about it. The hall seemed to quiet down at first as things appeared to return to normal. Not long after this though, the merchant met the bandits while visiting his relatives and died on the way, the house was in chaos, and the umbrella disappeared.
Eventually, the umbrella would be found by someone working for the manor. It was noted that the umbrella would generate magnetic fields at certain humidity levels, and was determined to be due to 'long-term exposure to a unique ecological environment'. However this is most likely some form of 'spiritual unrest' caused by Fan Wujiu, due to his death by drowning.