Gou Became a Necromancer in the Three Kingdoms

In a double time travel, Lu Bai fell from the pursuit of the magical undead into the purgatory of Xuzhou in the late Han Dynasty. He possesses [One Permanent Certificate], which allows him to permanently upgrade by summoning skeletons, but he can only endure it because he is weak. Cao Cao slaughtered the city, Changxi abused the people, and his savior died tragically in front of him. He had a golden finger but was unable to save himself. Burning with anger, he fled into the wilderness, nourished his bones with corpses, and used the spirits of the dead to prove his truth. Both worlds are hell, let's see him crush the bandits with his white-bone soldiers and sweep across the Three Kingdoms!