Board Thread:Warhammer 40k General Discussion/@comment-7186329-20130329201743/@comment-6078851-20130417142457

if all the original space marine legions were still around (and loyal) and worked in concert with the sisters, the guard, the mechanicum, the inquisition and the tau, eldar and necrons then they might be able to, not necassarily win, but hold them at bay. that's my take on it.

i agree that deamon armies would be the single best force to combat the tyranids, but while tyranid organisms don't have a presence in the warp, 'the shadow in the warp' is technically the hive mind's presence in the warp (it's a singular force and not one per fleet). this means that as the hive mind continues to wake up and 'the shadow' gets bigger there's a possibility that it could simply smother the gods. this is another reason, alongside tyranids eating all of sentience, for the gods to fight them.