How do I get vile powder?
Solution 1:
You can craft it from Vile Mushrooms or you can buy it from the Dryad during a blood moon.
Solution 2:
you can buy the vile powder anytime from the dryad(boss beaten required)or you can craft it using
1vile mushroom(makes 5 at a time)
this requires an alchemy station/bottle on a table/crafting table