These are chat archives for BSData/wh40k
Well in 30k, The Lion has been written to be fiercely loyal in the Horus Heresy Novels. He came to Macragge to kick Guilimans butt since he thought emp dead and was of the oppinion that noone should wield that power except Emps himself. There are other quotes from him like when he charged a battle line bringing a world into compliance doing a ritual muttering to himself like "one more world for you father.. one more world". He also fucked over Corax when that one confronted him with a vision of his future about a doubt in his loyalty with which the Lion responded with ramming his sword through him telling him he doesnt care, since "Loyality is it's own reward".
In 40k, the DA have some older fluff which connect them to some disappearings of loyal forces after they got a sniff of the Fallen. No downright proof though, some abandonment of battle lines when Fallen were sighted etc.
Compared to, lets say, Blood Angels which go berserk and slaughter Guardsmen or Space Wolves which open fire on Sisters and Inquisition ships thats nothing too special.
Salamanders are the goodiest of the SM with their "Protecting the people"-Shtick, so I excluded them :P
So it's like, DAs kill friends when they see the Fallen.
And the Fallen are possibly another fraction of DAs?