Possible defects: marks on several corners, nicks on edges, silvering (shiny edges on front face), marked surface, etc
That opponent may repeat this process as many times as they choose
The massive card flow that people want for free in Commander and multiplayer lead them to attack each other, but not you, especially since they don't have to spend a card to get the card draw, so for them, this is free card advantage over time for each foe that attacks each other, and you'll draw more than the card it took to cast him in one or two turns
Players can't take any actions between the time you make that choice and the time creatures are returned to their owners' hands
Depending on your luck, your opponents or your Pokmon might be asleep the entire game making Asleep decks one of the most fun or aggravating decks to play in Pokmon TCG Pocket
Therefore, because of the absurd payoff for its mana value, Necropotence is the best of the best for MTG Black card draw