Perhaps in a future update would be a renewable way to increase your stats: Some three-star dungeon that rewards a Witch Bottle. Or, perhaps, a less efficient witch bottle: One which requires draining 15 servants, and therefore requires access to the Carnival. Perhaps 20 servants, if you wanted to add a second tier of upgrade then currently exists.
Expensive, certainly, but the only option for getting more then two permanent stat-ups. That said, redistributing points is enough for just about any content- Though quite expensive in terms of servants.