Omnath, Locus of All

Whenever Omnath, Locus of All deals combat
damage to a player, draw a card.
Landfall — Whenever a land enters the
battlefield under your control, add one mana of
any color that land could produce. Then if that
mana is {w}, you gain 2 life. If it's {b}, target
player loses 2 life. If it's {r}, Omnath deals 2
damage to target creature an opponent
controls. If it's {g}, destroy target artifact or
enchantment.