Raw Source
HidePseudoAvatar / Hide pseudo & avatar 

// ==UserScript==
// @name         Hide pseudo & avatar
// @namespace    https://www.jeuxvideo.com/
// @version      0.1
// @description  JASSUMEPAS
// @author       hidpseudoavatar@jvc18-25
// @license      MIT
// @copyright    2021, HidePseudoAvatar (https://openuserjs.org/users/HidePseudoAvatar)
// @match        https://www.jeuxvideo.com/*
// @grant        none
// @run-at       document-start
// ==/UserScript==

(function() {
    'use strict';
    var pseudoSelector = 'body > header > div.jv-header-top > div > div.jv-global-user > div.jv-nav-account.jv-nav-account-user.dropdown > div.nav-link-account.js-account-id > span.account-pseudo';
    var avatarSelector = 'body > header > div.jv-header-top > div > div.jv-global-user > div.jv-nav-account.jv-nav-account-user.dropdown > div.nav-link-account.js-account-id > span.account-avatar-box'

    new MutationObserver(function(mutations) {
        if (document.getElementsByTagName('h1')) {
            var pseudo = document.querySelector(pseudoSelector);
            var avatar = document.querySelector(avatarSelector);
            if (pseudo) {
                pseudo.remove();
                avatar.style = "null";
                this.disconnect();
            }
        }
    }).observe(document, {childList: true, subtree: true});
})();