Prehistoric Aquifer

Aspect (If this spell entered the battlefield and
it wasn't cast from your hand, exile it)
When Prehistoric Aquifer enters the battlefield,
return each opponent's creature with a mana
value X or less to their owner's hand, where X
equals the number of cards in your hand.
If you would draw a card except the first one you
would draw in each of your draw steps, draw four
cards instead.