Skyshroud Cutter

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

Qasali Ambusher

Reach
If a creature is attacking you and you control a Forest and a Plains, you may cast Qasali Ambusher without paying its mana cost and as though it had flash.

Flare of Cultivation

You may sacrifice a nontoken green creature rather than pay this spell's mana cost.
Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Rushwood Legate

If an opponent controls an Island and you control a Forest, you may cast this spell without paying its mana cost.