Why does they say dank Farrik?

"Dank farrik" has been used a couple of times on screen, and its context makes it pretty clear that it's an exclamation of frustration or, to be more...

Are the Dark Angels heretics?

By going to Istvaan, the Dark Angels – all Dark Angels - would be seen as traitors and heretics however vociferously it might be denied by their primarch....