How does Words of Waste interact with Varina, Lich Queen?
You will be able to replace each draw with Words of Waste, however you will still discard the full amount. Additionally, you will have to activate Words before Varina's ability resolves as it creates a replacement effect

From the Gatherer Rulings for Varina:


  The number of cards you discard and the amount of life you gain are both equal to the number of Zombies you attack with, even if you draw a different number of cards somehow


emphasis mine