Saying something 'ist kreig' means it is extreme, or 'cool' in a black-metal-fan sort of way. Black metal fans often use it jokingly if they are talking about something that is far from extreme or cool in a black-metal-fan sort of way.
1# Immolating monks ist kreig.
2# Guy 1: what the fuck? Why did you buy a rabbit?
gUY 2: Snowy the Rabbit ist kreig.