Sadly there's no "effective" way to block a user here, you still see their topics. You can use some plugin to remove them from your page though, here's one way to do this using GreaseMonkey :
Code:
// ==UserScript==
// @name SuperScriptOfDoom
// @namespace bananas.com
// @description Removes threads containing specified words in title
// @include http://www.mmo-champion.com/forums/*
// ==/UserScript==
var ignored = [ "(GGT)", "NRA", "Police", "cannabis", "gender" ]
var regEx = new RegExp("(" + ignored.join("|") + ")", "i");
var divs = document.getElementsByClassName("threadbit");
for (i=0; i<divs.length; i++)
if ((divs[i].getElementsByClassName("inner"))[0].innerHTML.search(regEx) > -1)
divs[i].style.display = "none";
Just fill the var ignored = ... with every word you don't want to see in any thread title. (this right there is just an example, not what I use)
This works solely on thread title, we don't know who created it when threads are listed, so there's no way to hide thread from a specific user, just hide threads having specific words in title.
Of course, use at your own risk, warnings blabla, no warranty blabla, not optimized blabla, your computer explodes not my fault blabla, all that.