I have been using my 4th horseman for quite some time now and I have noticed that occasionally if I am right up in an enemies face, literally touching them, and killed them with the barrage of shells fired from this weapon and every now and again it seems to make me die to the architects and I have no clue, is it some kind of firefly that kills you I have no clue but I have searched the internet and nobody seems to know it's hidden perk, maybe this is it?