Tallymen
The Tallyman (not to be confused with the Tallyman of Nurgle) is the (in)famous chump from the Death Guard trailer that we all know and love. He is quite known for the fact that, in the grimdarkness of the 41st Millennium, the forces of Nurgle somehow still use a fucking abacus of all things. Anyway, the Tallymen act as spiritual leaders of the Death Guard, and are rough analogues of the regular old vanilla Dark Apostles.
Overview
Part priests, part demagogues, part metaphysical scribes and quartermasters, and part abacus uses, these zealots stride to battle festooned with the trappings of their strange craft. Upon their shoulders the Tallymen bear huge vox speakers through which their voices boom. Their incantations are endless, a drone of counting. Tallymen are the preachers of the Sevenfold path, emphasizing the number of Nurgle, seven in all its forms.
But perhaps the most notable feature of the Tallymen are the tomes they carry, filled with the woes inflicted on the enemy and other information relevant to the Plague God. This is when they actually use their stupid looking abacus. They count spent shells, wounds inflicted, brothers resurrected, disease spread and the number of screams that can be heard. They count the number of flies in the air and the number of slain. Always they tally the unholy seven, and in so doing they somehow invoke Nurgle’s boon. Nurgle’s faithful are empowered and inspired by the Tallyman’s count. Yes, you heard us right. These guys boost military effectiveness with the power of MATH! Who new the children of Nurgle were such bookworms eh? Ha! I fucking knew you and your sons was a bunch of closet NERDS! You and that Dog Fucker Leman can both suck my hot, geeky, red-tipped cock! GET THE FUCK OUT OF MY FACTION'S PAGE MAGNUS! Anyway, they don't use math, they use numerology, always trying to find the number 7 as a pattern in the chaos around them - something which is always possible, thanks to confirmation bias.
Eh-hum, anyways, on the battlefield, Tallymen are terrors, yet at all other times their order is isolated and secretive. Long ago, Mortarion entrusted them with the numerological codes to unlock the hidden vaults on the Plague Planet where the Death Guard keep their most appalling viral weapons. Such strains are precious and irreplaceable, and not lightly do the Tallymen part with them. The Death Guard Lord who demands access to these horrific instruments of destruction had best be prepared to pay a price to a Tallyman.