Those are all interesting, but if you roll a natural 20, you get to search your library for a card of your choice and then put it into play if its an artifact, or in your hand if its anything else
Most players aren't huge fans of the set, and I see where they're coming from
We wrote a whole post addressing the question: What are MtG Proxy Cards
Hold on to Prince Eric, Seafaring Prince to keep her safe, and plenty of the healing cards like Healing Glow and Julieta Madrigal, Excellent Cook , and you should be able to keep Isabela in play long enough to get you the win
Decks vary how many copies they play based on how reliably they want to have a copy once they hit seven mana, which is usually a question of how often they need that boost to win the game combined with how much they need to sacrifice to make sure they get that far