Walden-3 Shelter

When Walden-3 Shelter enters, if more {b}
was spent to cast it, breach it, and, if more {g}
was spent to cast it, unseal it. Then, surveil 3.
breach—Sacrifice Walden-3 Shelter. Create
three Treasure tokens and draw three cards.
unseal—Walden-3 Shelter gains "At the
beginning of your end step, for each {g} spent
to cast Walden-3 Shelter, create a 1/2 green
Human Scout creature token with reach."