New potion: Toxic Concoction (SS v1.0.0) (Patreon)

The recipe for this new potion can be earned during the post-game otherworld exploration activity. It's a potion that allows you to instantly win in combat, effectively skipping the whole fight. They're relatively expensive to make (and to sell!), requiring 2 agates a piece, among other things, but by the time you unlock them, you'll probably be able to afford as many as you could possible ever need.