Teferi's Puzzle Box

Each player may play an additional land on each of their turns.

At the beginning of each player's upkeep, if that player has no cards in hand, that player draws three cards.

At the beginning of each player's draw step, that player draws two additional cards.

At the beginning of each opponent's upkeep, this creature deals X damage to that player, where X is the number of cards in their hand minus 4.

At the beginning of each opponent's upkeep, this creature deals X damage to that player, where X is 3 minus the number of cards in their hand.

At the beginning of each player's upkeep, return to its owner's hand each creature that player controls with power greater than the number of cards in their hand.

At the beginning of each player's end step, if that player has 5 or less life, this artifact deals 2 damage to that player.