Disclaimer: I hate vanilla JS

I wrote this some time ago, and I updated it just to fuck around. It will make long comment chains unreadable if they have the blocked person multiple time in a thread, and I haven't done more than a minutes worth of testing. Good basis for making your own script though.

let userNames = ['yourejewish']; // lower case
Array.from(document.querySelectorAll('.lv0, .lv2, .lv6, .lv20, .lv30, .lv50')).forEach(function (el) { 
    if(userNames.some(function (un) { return el.innerHTML.toLowerCase().indexOf(un) >= 0; })) { 
        if (el.parentNode.className.split(' ').indexOf('commenthead') >= 0) {
            let head = el.parentNode; // .commenthead
            if (head.className.split(' ').indexOf('collapse') >= 0) {
                head.classList.remove('collapse');
                head.classList.add('expand');
            }
            let headParent = head.parentNode; // .commnotblocked
            headParent.querySelectorAll('.votecomment, .content, .bottombar')
                .forEach(function (hide) { hide.style.display = 'none'; });
            headParent.nextElementSibling.style.display = 'none';
            el.closest('.commentrow').style.opacity = '0.3'; 
        }
        else {
            el.closest('.post').style.display = 'none'; 
        }
    } 
});