Invigorate

If you control a Forest, rather than pay this spell's mana cost, you may have an opponent gain 3 life.
Target creature gets +4/+4 until end of turn.

Skyshroud Cutter

If you control a Forest, rather than pay this spell's mana cost, you may have each other player gain 5 life.

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Forest

Kavu Predator

Trample
Whenever an opponent gains life, put that many +1/+1 counters on Kavu Predator.

Grove of the Burnwillows

{T}: Add {C}.
{T}: Add {R} or {G}. Each opponent gains 1 life.

Manamorphose

Add two mana in any combination of colors.
Draw a card.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Abundant Harvest

Choose land or nonland. Reveal cards from the top of your library until you reveal a card of the chosen kind. Put that card into your hand and the rest on the bottom of your library in a random order.

Elven Farsight

Scry 3, then you may reveal the top card of your library. If it's a creature card, draw a card.

Grollub

Whenever Grollub is dealt damage, each opponent gains that much life.

Mountain

Nature's Claim

Destroy target artifact or enchantment. Its controller gains 4 life.

False Cure

Until end of turn, whenever a player gains life, that player loses 2 life for each 1 life they gained.