Seriously, stop there and let your imagination take over. Most agree that Total War put him in the right spot for where he'll end up but the timeline will now never be advanced.
Unfortunately, one more book featuring Malus does exist, BUT. This is an End Times novel, where Games Workshop was rapidly killing the entire setting off. For the sake of your sanity and love of Malus, DO NOT READ IT. With that warning out of the way, the aforementioned fail is called Deathblade by CL Werner.
Ask not the Eldar a question, for they will give you three answers; all of which are true and horrifying to know.