Devil's Disciple this was the technique they were bestowed upon by Wang Ling. A vial of his blood to strengthen the remaining cultivators at the stage of Ancestors. The vial of his blood consisted of both lineages, and whatever they are most suitable with would get a part of the two lineages.
The idea was taken when Wang Ling gave Chang Ping a piece of his blue qi. For a moment she unleashed power that was many times her own but at the cost of her sanity and rationality. Wang Ling couldn't split his essence, or rather he chose not to.
The danger of weakening himself would severely change the course of the future, but drawing blood from his own was different. His blood was infinite, but only a few could accept his blood, Chang Ping was one of them.
From the blood she was given, she extracted two wings from a single vial. She had not finished digesting the vial of blood so right below the second wing was a smaller wing growing still.