Lorewise, excess anything empowers Slaanesh. Which would include excess disease, so long as they exult in it. There's a reason Slaanesh is one of the strongest Chaos entities, despite being a relatively young demon: Everything is praise, even praise for the competition.
Are you allowed to switch chaos gods? Won't slaneesh be pissed?
Perhaps this one follows chaos undivided...
Lorewise, excess anything empowers Slaanesh. Which would include excess disease, so long as they exult in it. There's a reason Slaanesh is one of the strongest Chaos entities, despite being a relatively young demon: Everything is praise, even praise for the competition.