Otherwise give them an alternative method of healing them that's not as taxing or dangerous as White Oil.
Maybe something that functions in a similar way to the way Gluttony Sin did, you can consume certain living creatures and heal back from permanent damage.
Otherwise, make it so that they can gather essence like witches do and heal a perm with it once they've got enough.
Maybe something that functions in a similar way to the way Gluttony Sin did, you can consume certain living creatures and heal back from permanent damage.
Otherwise, make it so that they can gather essence like witches do and heal a perm with it once they've got enough.