KissManga Cloudflare Challenge Anti-AdBlock Counter-Tamper.

kissMangaAntiAdBlockCF.user.js

// ==UserScript==
// @name         KissManga - AdBlock Tampered Cloudflare Challenge Bypass
// @version      0.11
// @author       Manciuszz
// @match        *://kissmanga.com/*
// @grant        unsafeWindow
// ==/UserScript==

(function() {
    'use strict';

    let footprint = document.querySelector("div[id^='cf-dn']");
    if (footprint) {
        document.cookie.split(";").forEach(function(c) { document.cookie = c.replace(/^ +/, "").replace(/=.*/, "=;expires=" + new Date().toUTCString() + ";path=/"); });
        unsafeWindow.t = window.location.host;
        unsafeWindow.k = footprint.id;
    }
})();

is there an easy way to get this to work with other sites that are using cloudflare?

It really depends on the website and their cloudflare implementation. If the tampering done was identical to this, then simply adding a new line like this

// @match ://my_tampered_website.com/

will solve the issue... but that's highly unlikely.