As the perfect pairing alongside the spirit token generation, we also expect there to be plenty of ways to boost the power of creatures, or even just spirits, either through instant spells or enchantments
Write "Fake" clearly on the card with a marker
The ward ability is very powerful, and sacrificing something legendary is a real cost
Like most Magic: The Gathering cards, the value of Aang and Katara depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Avatar: The Last Airbender Eternal)
It can power out spells during combat
In short, they like digging old things up