Those who picked up nether taint there eventually have nightmares, start physically weakening and withering, and then die. Up to you if you're a Nether Champion and want to RP that or not.
I already have the nightmares, plenty of them. As for the weakness, my character had spent 70-80 years bed-ridden whilst he taught someone Druidic techniques and minor magic to sustain his wounds, but I can manage with the weakness ^^
