Thousand-Face Thief

Modern transmigrator Song Hao falls into poverty but finds a magical face-changing mask that lets him transform into anyone he has seen. He uses the mask to revenge those who bullied him, disguises himself to accumulate huge wealth, and finally infiltrates the palace to transform into the emperor, controlling the treasury, passing the throne to the crown prince, and self-declaring himself the retired emperor while holding all the world's riches and enjoying power at its peak.