Kormus Bell [Limited Edition Alpha] Black Maro-Sorcerer's power and toughness are

Maro-Sorcerer's power and toughness are each equal to the total number of cards in all players' hands

change Halfdane's base power and toughness to the power and toughness of target creature other than Halfdane until the end of your next upkeep

Set: Zendikar Type: Legendary Planeswalker — Sorin Mythic Cost: {3}{B}{B}{B} +2: Sorin Markov deals 2 damage to any target and you gain 2 life

quoting Confucius

and Y is half the number of Forests you control

Kormus Bell [Limited Edition Alpha] Black Maro-Sorcerer's power and toughness areSet: Limited Edition Alpha Type: Artifact Rare Cost: {4} All Swamps are 1 1 black creatures that are still lands.