Simple question, this: does a potion of purity still remove the haematic curse? Or is the only way to remove one instance of it, the consumption of one haematic phylactery?
The debuff is no longer considered a curse, so curse removal won't fix it anymore. Each phylactery will remove one stack of the buff, and that's the only way to get rid of it.
It's a good thing that some Wizardlands have free haematic phylacteries then to find. Once I stack enough of those I'm chucking all my regular healing potions into a corner of my pocket dimension.