parashautoreplace.user.js

// ==UserScript==
// @name         ParashAutoReplace
// @version      0.1
// @description  ParashAutoReplace
// @author       You
// @downloadURL https://pastebin.com/raw/tfsXs8wJ
// @updateURL   https://pastebin.com/raw/tfsXs8wJ
// @match        https://2ch.hk/po/*
// @grant        unsafeWindow
// ==/UserScript==

(function(window) {
    'use strict';

    function replace(str) {
        return str
            .replace(/Светов/gi, 'Све​тов')
            .replace(/Навальный/gi, 'Навал​ьный')
            .replace(/Путин/gi, 'Светов');
    }

    var send = XMLHttpRequest.prototype.send;
    var open = XMLHttpRequest.prototype.open;
    XMLHttpRequest.prototype.send = function(data) {
        try {
            if (this._method == 'POST' && this._url && this._url.indexOf('posting') != 0 && data.has('comment')) {
                var comment = data.get('comment');
                data.set('comment', replace(comment));
            }
        } catch(e) {
            console.log(e);
        }

        return send.apply(this, arguments);
    };
    XMLHttpRequest.prototype.open = function(method, url, obj) {
        this._method = method;
        this._url = url;
        return open.apply(this, arguments);
    };

})(unsafeWindow);