Where is the Wolong red night suit?

You can only get it by buying DLC. According to the official website query of Wolong: Sky Fall, the red night suit of Wolong: Sky Fall is a joint-name suit of Never Robbed, which can be activated in the game after purchasing DLC. Wolong: Heavenly Descent is an action role-playing game, which was developed by TeamNINJA, a studio of Glory Tekumo.