Just like with Emeria Angel, often itll arrive on Turn 5 with an Opt, where Emeria Angel arrived with a land drop
Whatever you decide, I'm now a fan
This effect can only be used once per turn, but considering players only put that much on the board to end someone, once per turn might actually be too frequent
Deal with the Devil: His deal with the Door is treated as this, with it being stated that he'll gain great power, but lose what he holds most precious (and he comes up with about half a dozen examples of what that is by the end of the series, with it being left deliberately ambiguous as to what Yuma gave up)
Typically, the extra cost for the Treasure tokens is worth it, as it gives you more mana flexibility later down the line