At least the Wraithguard will be immune to Poison (at the very least) and possibly have the "headshot" being in the chest (soul stone) instead of the actual "head".
Luckily EC follows the lore more closely than the TT, and you can't really poison something "dead" and the poison wouldn't work then, just like you can't poison a robot or a rhino (unless you count corruption as poison). Also, Nathan said the Wraithguard would be immune
You make it sound like the hyper advanced race of sadists would not take the time to make their poisons corrosive to be effective against a) ectoplasmic warp manifestations b) self repairing robots c) virulent fleshbags and d) the constructs of their lesser kin. After seeing what snake venom can do to people, I'm quite willing to accept a poison effect that can melt wraithbone and necrodermis. Also RIP painboy.
It wouldn't be poison then, it would more likely be some powerful acid or alkali which would indeed damage the wraithbone (and everything else). According the the Marrian-Webster a poison is "a substance that through its chemical action usually kills, injures, or impairs an organism". The important part there is the word "organism", as a Wraithguard is not an organism and nor are other constructs or vehicles, partially due to the fact that an organism is a living being or system. The can obviously exists poisons that are capable of damage non-living matter, but that will not be due to the poison itself, but due to the poison containing chemicals which in some way reacts with the inorganic matter in some way, like if the poison was acidic too. Some venomous snakes inject digestive substances alongside their venom to speed up the digestion process, this is also seen with some spider species, like the brown recluse spider, which venom can dissolve flesh. Examples of poisons that are also acids: - Hydrofluoric acid - Fluorosulfuric acid - Chlorine trifluoride (this one is so silly dangerous it is almost funny. It is very toxic, extreme reactive with most organic and inorganic compounds including glass, will initiate combustion of many non-flammable compounds without the need for a heat source, it is more oxidizing than oxygen meaning that it can ignite even ashes and sand ). There even is a TV Tropes on the matter: http://tvtropes.org/pmwiki/pmwiki.php/Main/PoisonIsCorrosive
40k is reliant on tropes. Poison is a catch all that includes a crystallizing virus, not going to argue the semantics of that. Wraithguard/necrons/daemons/nurgle marines are vulnerable to poison, and in fact the best counter to a wraith army (when that was possible) was poison. I'm a big TT fan, that's all. If they go a different direction that's their prerogative (those painboyz though) and I'm not upset by it. But there is precedent for wraith taking poison damage.
*Ahem* Friendly neighbourhood Haemonculus calling in, you can INDEED poison wraithbone constructs. With SOUL-poisoning, as that's the only relatively organic part of them left. Physically you want acid. Lots of acid. You know who else has lots of acid for sale? This guy! Buy two vials for the price of three. But the poison that painboyz and apothecaries are packing won't really do anything.
You say that like an accelerated fungi used as a clotting agent with an innate psychic field isn't harmful to a warp-generated material. You know what wraithbone is like? A rock. You know what eats rocks? Fungus! WAAAGH!!!
Hah! That is where you have failed, for it is not mere rock, it is a warp generated material with bone-like properties, and can take a lot of punishment, but rock it is not! Regardless, the only way you're truly poisoning a Wraith construct is with something arcane that damages their very soul itself. Acid doesn't count. And even with some form of soul-poison, there are Spiritseers that may completely negate the effect by just guiding them.
I find myself relying more and more on point form to avoid overly long posts. -Again, poison of the trope variant. Doesn't matter if it's a poison, venom, toxin, virus, phage, bacteria, acid, alkaline, or crystallizing compound. We're in 40k, the science lost to fantasy long ago. -Wraithbone is a rock. Is it malleable, elastic, or particularly conductive (thermal or electrical)? Nope, it's a rock. Crystal if ya wanna get crazy, and metal if you go astrophysical on me. (I even used the term warp-generated material first...) -I see your special warp rock and raise you bio-engineered fighting warp fungi. That's right, the Old Ones left two psychically charged races. -Don't care about the spirit stone, just need to kill the construct. Mobility kill you might say. In conclusion Ork fungal poison is a totally legit method of destroying wraithbone. The moral of this story is that if you want your constructs to be immune to poison, play D&D.
