Sorry to leave you hanging.....
Had to actually work for a bit.
Flesh Tearers - I'll leave it to your imagination
Alpha Legion - Sneak in, go, convince someone else they did it
Iron Warriors - It involves chains and trenches
Lamenters - Go, repent, CRUSADE!
Iron Hands - Mechanized, works like an Air Lock in deep space
Luna Wolves - Go, then get mad no one else thinks it's special, turn to Chaos
Word Bearers - Go, build a Temple around it, demand worship
Death Guard - It's white, has lots of flies
Emperor's Children - Involves lots of noise, when done, Guitar Solo!
Thousand Sons - Close one eye, devine the problem, produce sand
World Eaters - Two words: Chain Axe
Night Lords - Under cover of dark in the precise spot
Legion of the Damned - It just appears, catches on fire
Did I forget anyone?