Board Thread:Warhammer 40k General Discussion/@comment-6589306-20130228113457/@comment-6078851-20150107163340

the necrons have possibly the best chance against the tyranids currently within the galaxy, but they are by no means guaranteed victory. necrodermis is a living metal, and given that complex lifeforms need metals as part of their biology, necrodermis is almost certainly digestible by tyranids, so necrons do have biomass to contribute. also, necrons aren't indestructable, they are very destructable they just have reanimation protocols, which can be rendered ineffective from enough damage, as well as their teleport-recall function, which too can be rendered ineffective, or even detrimental to necrons, if a teleport-recall hub-world has been defeated by tyranids, in which case necrons being teleport-recalled would be fast food :P

the thing is though, necrons might be able to hold off the tyranids currently within the galaxy but they are essentially fighting off the pinkie-fingernail of tyranid-dom, and the rest of the hand isn't far behind, followed by the arm, torso etc. the key to tyranid survival is partly their adaptability but also their unimaginable numbers - they dwarf everything with their numbers and will consume everything because of their numbers, it's just that most of them aren't here yet.

no-one can survive against tyranids on their own, as has been pointed out various species have various advantages and disadvantages, but no species have the capability to go it alone. the only way to not just fend off but actively defeat tyranids is with an unprecedented alliance. not just an alliance between the various species but with the chaos gods also: chaos daemons would be the single greatest asset against tyranids as they would truly leave no biomass, and as tyranids will consume all corporeal life they will effectively, and indirectly, kill the chaos gods too, giving the gods an incentive to join such an alliance.