It draws equal to your biggest power, and note that's not targeted, but just when it resolves, and then instant speed is great too since you can do it when it's removed to draw or just to dig or EOT to just use your mana
Lock and Key is included
Lets look through the other top Pioneer decks based on PlayingMTGs Tier List from a week ago from the perspective of Archfiend vs Sheoldred
It's out of place in many decks, where its reasonable effect isn't worth the effort of casting it and then finding a way to destroy it
Marking a transition point in holofoil style, the classic starry holofoil style found on English copies Pokmon TCG cards was still the most common way to find fossil cards
However, do note that the huge excitement around Disney Lorcana from Disney fans, trading card game fans and collectors alike has meant that many sets are still difficult to find, just as they were for the initial set, The First Chapter