There is nothing you can do about it, the best thing to do is to add your patron link with the chapter so it get promoted to even more readers. You are kinda lucky tbh, since you can still get new readers to your patreon, imagine other original fic author who depend on the chapter unlock for money and these pirates comes and steal it all without even leaving privelege chapters. I don't see how you can fight this any other way since there's no way to stop people from copying text.
I looked it up and the guy is Nyawdao3 ladies and gentlemen. I looked up with the words Uchiha and it came up... At first I looked up Stormwind Mage God but it wasn't Stormwind Mage God that was stolen. And yes it is considered stolen because our Translator worked hard to translate both novels... The original fanfics may not belong to Read-And-Chill but the translation is a culmination of his hard work.