My biggest annoyasce with this film:.
Is that the Chaplain did nothing but that silly "Burn Heretic"
Seriously, Chaplains are supposed to be the most devoted, the most hardcore of all Space Marines, often throwing themselves at their enemies to show their devotion by delivering His retribution by using the Crozius to do what it is very good at and bash their heads in, but no, he does his death ray and thats pretty much all he contributes.
Would have been a lot better if he'd have thrown himself ta the Chaos Marines and bashed a few heads in, or even, barely survive being shot at the end, even if it was only to crawl to Proteus and inspire him with shouts of zeal and fury.