The people of my flat medieval fantasy world have found a rune that generates infinite boiling water, and they want to use it to kill each other. Sadly the water cannot be made with momentum included, so they have to find an effective way of throwing the water to the enemy.
In one of their attempts they tried putting it inside a hollow metal cylinder, link one end to a set of chains that is connected to a long stick and make a hole in the other end of the cylinder. Basically making a pseudo-flail that when spun would spray hot boiling water out of the far end.
Assuming they are fighting in a flat tropical environment, how effective would this weapon be? As in how far can this weapon reach and how much armor can it penetrate while still causing second degree burns?
Edit: The rune creates boiling water from nothing, so no water needs to be carried. The water is created continuously at a rate around 0.1 litre per second. For the size and weight of the weapon, it's similar to a two handed flail though maybe with a slightly bigger head.