How to bite your hand before using a psychic?

The first key of blood communication is blood, because the blood contract is signed with the psychic, so the psychic must know who is calling him through the medium of blood. The signer has blood stains on the blood contract, and once the psychic is authenticated, he can call it. Therefore, the blood psychic will bleed before channeling, and will concentrate the chakras and blood on the signing hands as a summoning medium. Then another key is printing. All blood mediums use the same seal, and the order is Hai, Xu, You, Shen and Wei.