Board Thread:Warhammer 40k General Discussion/@comment-86.186.232.255-20130517161917/@comment-6078851-20131009010332

the necrontyr (pre-necrodermis) as a fleshed race were the most prone to disease and cellular degeneration, so maybe before the c'tan changed them their collective suffering might have influenced nurgle's birth. it's around that time that the old ones tampered with the warp which allowed chaos entities to manifest, and as the necrontyr weren't particularly psychic, instead of an eye of terror style event (which was heavily influenced by the might of eldar psykery), maybe nurgle was birthed as simply a mild conciousness in the warp, and after that he grew in power from the suffering of the other races.