Lightning Greaves A cheap but brutally effective card often held to be the premier protection piece
(As an optional house rule, many people elect to shuffle all those planes together for the gameup to you and your group if you want to do that.) The first player reveals the starting plane from their deck
Sure, you have to give up four damage to get Refraction Elemental, but it should more than make up for this in just one turn on the battlefield, which should make defeating the battle worthwhile pretty often
Alternately, you can simply keep Boromir away from skirmishes as best you can and use his vitality pool for exertions
Some might say it was a Tough Cookie to swallow, and speaking of which, Tough Cookie is another great payoff for aggressive green decks
Flinging two Scorching Dragonfires or Lava Coils every turn is good value