i found a physick flask on top of the shack like you guys said
i thought it would recharge at every grace like in elden ring and used it in the rain but:
1 it didn't stop rain damage
2 it didn't recharge at the grace

so i should pick this up at the start of the game and keep it until the nightlord?
it's worth 25k runes so that's nice, but i hoped to use it all run long