It's a good read by any mean, but there are a few issues I wonder about.
The Elysians shall be elite paratroopers, they seems here like they are cattle not elite soldiers. The followers of Chaos being organized, that sounded so odd that I at the first read assumed them to be Imperials. Okay might be my interpretation, but I would have added a section where Haum bested Kolan and such.
And there were a place were Haum was described as yelling something in praise to Khorne. Why not let him yell Blood for the Blood-God! or that other catchphrase they use? I mean Khornate fanatics are fanatics. They yell one phrase really loud.
Also the fighting, Haum seems to be heavily armoured. He should go in and feed the guardsmen their entrails not just shoot at them. He is a Khornate fanatic, and that would seem more like them. I can understand the need for him to take out alot in ranged combat, but if I were you I would have Haum topple a column or a statue of Empy on the hapless Elysians, and then you can add some humor in it was the Empror squashed his own weaklings.