I love the heroes.xml customisation options! Could you add cost modifier, starting level and soulbound artifacts to the categories? Cost modifier is a gold value which can be positive or negative, which gets added to base hero cost and per level modifier, but only applies for a particular hero. Soulbound artifacts are separate to regular artifacts category. Soulbound artifacts are fixed to the slot they start in, and are not lost when that hero loses a battle, and can't be moved or transferred to another hero.
Would you be able to add these three categories?