Marcus, Order and Chaos

When Marcus, Order and Chaos enters the battlefield, all white and black cards
on the field gain Lifelink. On your
upkeep step, you can play a Ying Yang
spell for three life instead of for mana.
{p/w}{p/w}{2}-All white creatures you control switch toughness with power.
{p/b}{p/b}{2}-All black creatures you control become
1/3 Horrors with deathtouch.