Malignant Plaguecaster
The Malignant Plaguecaster or simply known as the Plaguecaster is one of the pestilent sorcerers of this pox-ridden Legion of the Death Guard. Although Papa Nurgle might not be too keen on playing wizardry, he does acknowledge its benefits rather then going into an autistic rage at the mere mention of it. Thus, the Plaguecasters are born. Essentially Nurgle Sorcerers without the trickery and JUST AS PLANNED but with more STD's and AIDS. The Plaguecaster throws out a concoction of magical and heretical diseases and corruption at the enemies of Nurgle.
The bloated bodies of Malignant Plaguecasters have become living conduits for the Garden of Nurgle’s toxic miasmas. Flesh-eating spore clouds, droning plague flies, vomitous mists and plague-laden corpse gas roil within the Plaguecasters’ guts, at times straining their skin to bursting point. With retching exhalations, the Plaguecasters blow these lethal clouds across the battlefield. Around a Plaguecaster Warriors collapse, choking upon their own rotting lungs even as their flesh blackens and liquefies. Armor corrodes and weapons malfunction as they are eaten away. Even sealed fortifications offer no protection. They are feared as much as they are resilient.
As per usual, being filthy psychic sorcerers, Malignant Plaguecasters aren't too hot with their pappy Morty and is often treated as that red-headed stepchild of the Death Guard. Ironic since Morty and the Death Guard are so filled with nasty Warp Bullshit that they are more related to those filthy psychic sorcerers than the pure non-psychic ubermensch. Que ironic laughter from the Malignant Plaguecasters.
Malignant Plaguecasters are armed with a corrupted staff, a bolt pistol, blight grenades and some krak grenades, thus they aren't too hot around guys that likes to get in close and personal even with its disgustingly resilient rule. Hence, it is best to use them as a support unit, chucking as much shit and flies at your enemies to distract them long enough for that pus-ridden fuckhead with the bell on top to go full 300 on your ass. Seriously combine the annoying attacks from the Plaguecaster with that of the leadership/speed buff/nerf of the Blightbringer is potentially Rage worthy.
What you want for your silly looking Gandalf the Vile wannabes is in their psychic powers. Whilst not the touhou-esque psychic bullet rape that is Ahriman or Magnus (Who even they are nerfed), the Plaguecaster benefits from its Pestilential Fallout rule in which every time it passes its psychic test on a 7 or more result, the nearest enemy within 7" suffers a mortal wound after the effects of the psychic power has been resolved. Literal shitstorm indeed.