Invasive Interrogation

Cruelty — (You may reduce this spell's mana value equal to the amount of life lost by your opponent this
turn. Your opponent must lose more life for a spell to benefit from Cruelty again in the same turn.)
Target player reveals their hand. You choose a nonland card from it. That player discards that card.
It took only a day to gain the knowledge of these new creatures, but the process proved too enjoyable to simply discontinue.