Daedalus81 wrote:
Ally in Ahriman. Bring Death Hex for the wraiths. -1 to hit to neuter the Tau against your important units among other useful buffs.
I would definitely look into at least a Chaos Marine add on if you are having trouble with Wraiths. Death Hex will strip the invulnerable save of any model near the caster, it's a tricky cast at 8, but using
CP will help, and Ahriman does get bonuses to fast if you go 1ksons. You will absolutely wreck wraiths after stripping their saves.
Zerkers should also annihilate them on the charge, since they wound on 3s with their axes... And with a bucket of attacks will push through that 3++, especially with a second or third fight phase! Wraiths cannot afford to be intercepted by Zerkers