Limit the number of Phantoms

Phantoms are annoying, especially on big server where it's impossible to sleep. The number of phantoms per night should be limited.

Once you kill the phantoms, there shouldn't spawn new ones for the rest of the night. You get peace until the next night.

On the first night, there should be one phantom, on the second night there should be two together, on the third there should be three together, and so on. After a week in-game, the number caps at 7 and it won't go higher than that.

So, in the worst case, on a server where no one can sleep, you'd have to fight off no more than seven phantoms per night. That's certainly better than the constant bombardment we have now.