Aaron Dembski-Bowden
Aaron is not Graham McNeil.
A writer of 40K awesomeness for the Black Library and occasional fa/tg/uy. He's also involved in the fan project The Lord Inquisitor, but he's just one of many. He also has a blog
A younger, even sexier version of Dan Abnett with a bigger dick and a smaller word count. Member of the Bald Brotherhood of Awesome 40K Writers, also known as the Bald Bards of Steel.
He wrote the short piece of fiction, Dude, Where's my Land Speeder?.
Aaron Dembski-Bowden is also well-liked by Daemonhunter lore masters, due to his effort in at least making the new Grey Knights lore more palatable (given the rage-inducing material he had to work with). Where there was once just Mary Sues after the Glory Days of 3rd Ed, now there is at least a semblance of deeper character to the 5th Ed Grey Knights outside the idiocy written by a certain Spiritual Liege. He even ties them back into threads left from Ravenor, so that the influence of Saint Abnett can cleanse them.
He's also pretty well-liked by Ultramarine players for making them cool again.
In fact he's pretty good at making all factions awesome but imperfect. See, for example, his portrayal of Angron. While Angron is indeed a dreaded unstoppable killing machine, he's also a pitiful character who blames others for his problems.
He is quickly approaching Dan Abnett's record of number of beloved characters murdered. Seriously. Reading his books, especially the Horus Heresy ones, is like watching him rip your heart out and chew on it while he coos "Was it good for you too?"
Lest you think we're going soft, though, we should point out that he has received some pretty harsh criticism (...wait, where?) for his portrayal of The Emprah as a raging torrent of incompetence and jackassery the likes of which Earth had not seen since Mussolini made his last public appearance upside down at a petrol station (although, to be fair, he mostly portrays traitor legions who have a...less than positive view of the guy). Some have accused him of turning the Horus Heresy books into a public therapy session for his daddy issues, which, to be fair, is still better than comparable to CS Goto using his books as a public therapy session for his depression at not having the chops to be a Hollywood screenwriter. He also has a major issue of making the characters he likes look perfect while shitting on other groups see his Grey Knights book which is really just a Space Wolves wank. He also has very strong views on very debatable positions, such as Advancing the Storyline and Your dudes. (Explaining the company's policies isn't the same thing as "having strong views").
Chuck Wendig is his waifu.