Empress' Game: Make-up Master

Luna Wu, a modern killer who is skilled in special effects make-up, accidentally time travels to an ancient time and become the Premier's youngest daughter who is retarded. Faced with a number of bitchy girls, strange family members, a troublesome prince and a cunning lord, she overcomes all difficulties by using her special effects make-up and self-made props, and finally becomes the empress.

(Source: Webcomics)