YBC is Si Ying sister from 10.000 yrs. ago, her name is Mo NV.
The orphan demon children Si Ying and Mo NV are 2 demon kids who rely on each other. TH Dad, the previous God of War, Tianhao, MY’s Shizun, caught Si Ying & Mo Nv brought them the heaven realm to be made into walking corpse soldier to suck Demon (her own kind). Si Ying was abt to be selected but Mo NV stepped forward told Tianhao that she is stronger and will be more effective.
Si Ying was spared and Mo NV was thrown into the Fire Pot and her Demon essence is sucked out by Tianhao. Demon god 1.0 killed Tianhao saved Si Ying and brought her back to his palace. Mo NV body conditions is too dire and can’t be saved. DG made her into a weapon umbrella and gave it to Si Ying. SY becomes the devoted right hand to DG 1.0.
During the battle of Demon and God, U saw Mo NV came out fr Si Ying umbrella. She was attacked by Chu Huang and God of time; her soul was injured even more. DG 1.0 sent her to mortal world for 10.000 yrs. as mortal to repair her soul. In each of her reincarnation, she must experience injustice and suffering to repair her soul over and over again. Her reincarnation finally completed 10.500 yrs. later and her soul is fully repaired and she can return as Mo NV.
So that’s the story of and remember Mo NV is only a kid when she had to experience her sad