A naked general is fighting, with a flag with Cao written on it beside him.

Idiom: Go shirtless.

[Explanation] Go into battle with bare hands. Metaphor comes to power in person and carries out activities unabashedly.

[From] Ming Luo Guan Zhong's Romance of the Three Kingdoms: "Chu Xu got up, flew back to the array, took off his armor, was stiff all over, bare-chested with a knife, turned over and got on the horse to fight Ma Chao."