Violet Flash (Hard) is the first stage in Growing Purple.
Soon after stage start, a few Doge Darks come out one after another with a couple of Gory Blacks coming out too. Once you hit the base, a Shadow Boxer K comes out along with a Gory Black and a Doge Dark.
Start off by saving some money and leveling up your Worker Cat. When the Doge Dark / Gory Black come near your base, spawn Sexy Legs, Paris Catand UFO Cat. Go soft, you don't want to rush the base. If the base is hit, a mass of Doge Dark, Gory Black and the boss, Shadow Boxer K, will appear. Simply spam all the units and it's going to be very easy.
Strategy 2: Spam Kasa jizo.