Master of the Canvas: Whoever I Paint Can Transform into Them

While playing an ancient-style xianxia game called Sovereign, Su Xiaobai died suddenly. His soul was swept into a cultivation world, where he became Su Bai, son of the Marquis of Dingnan in the Great Chu Dynasty. After discovering he couldn't log out of the game, Su Bai used his keen eye to buy the damaged divine artifact Illusionary Spirit Brush. Hunted by his eldest brother Su Hao and Lu Qianxue, the most beautiful woman in the capital, he changed identities to flee and gathered resources to upgrade the artifact.

From then on, the world had a shape-shifting Demon Lord who didn't just kill people: afterward, he would also claim their families and sects, taking their place and living their lives. It was even more terrifying than simply killing someone and destroying them utterly.

(The protagonist is male. His transformations include both male and female forms. This is not a story about a man turning into a woman!)