User blog comment:Herzog de Puce/Baeny, the Mana Engineer/@comment-3148314-20140625100526/@comment-7709681-20140625223901

@ TwiceBorned: Wither reacts differently to Tenacity: This doens't reduce the slow, but increases the velocity of the total application.

Wither causes an initial slow that increases additivelly per tick over a fixed duration, what Tenacity causes is to make the ticks of bonus movement/attack speed reduction occur faster, thus, decreasing the duration of the effects.

But again, Tenacity's relationship with Wither makes its effects occur faster, not decreasing the effects.