Is there any conspiracy for the dark god to sign the master-servant contract in the novel "The Airspeed Star"?

There is a conspiracy. He wants to leave the dark place with Tianjing, because his strength is slowly weakening and he is dying. Finally, under the special circumstances of Tianjing (his adoptive parents and his mentor died), he tried to possess the soul of Tianjing, but failed and was destroyed. Not the power of Tianjing. Oh, good luck.