While the archenemy still chooses who they attack for any effects where it matters, because any of the heroes can block, it becomes a lot more straightforward: the archenemy attacks heroes, and the heroes attack the archenemy, each group with one shared life total
You choose a nonland card from it and exile that card
So many one-mana artifacts have been printed for Urza recently (Esper Sentinel, Portable Hole, and now Moonsnare Prototype as well), that playing it on Turn 2 is going to hit a large fraction of the time
Some paradox abilities count the number of spells you've cast from anywhere other than your hand that turn to determine the magnitude of their effects
[63] Additionally, the WPN maintains a set of rules for being able to sanction tournaments, as well as runs its own circuit