The tutorial is very confusing, it's really not clear that the potion is what makes it so you can disrupt the ritual (why do the cultists even have it? lol) and it wasn't obvious that the potion was filling from clicking the cauldron due to how slow it fills.
It would be better if, instead of a cinematic, the tutorial made you actually go through some actions of disrupting the ritual, then going back to the cauldron to refill, so you got a better idea of the gameplay loop.