The Brothers War brought some amazing powerhouses to different formats, but here are a few I believe are being overlooked. Keep these in mind when Deckbuilding.
Being able to permanently buff your entire board with two +1/+1 counters isn't something to scoff at, and will certainly help you push damage through late game, being able to also exile everyone's graveyards with some life gain tacked on (both at the same time might I add) really pushes this card over the top. While the other two options are underwhelming for the cost, this card makes a unique addition to any creature deck looking to go wide late game.
While the static ability isn't going to make any waves, paying three mana for a creature that adds two mana isn't a bad trade off. This card doesn't tend to trigger anyone's danger meter for immediate removal and will definitely come in clutch to help you cast those big creatures a couple turns early. Even better, Gwenna can be your commander for a "big creatures" matter green deck.
While not as underrated as the others, I haven't seen Fauna Shaman as much as I thought I would. This card has been a powerhouse in multiple formats to the point of once being $20 to pickup. Thanks to its recent printing you can snag them for under $5 (as of writing this). This card single handedly turns any creature card in your hand into a 1 mana creature tutor. Honestly if you aren't running this in any deck relying on creatures (what are you doing?)
Tired of the rampant fast mana and broken things any artifact deck is trying to do? This card is only rivaled by Seeds of Innocence which is a $20 card on the reserve list AND that one doesn't destroy Enchantments. This card is an outright powerhouse.
It says Draw three. OK OK, a 12 mana investment to draw three cards is really bad, but we're not here for that. This card comes down as early as turn one, and starts beating face with 5 unlockable damage on turn two. And if you happen to have an extra 6 mana late game, that draw three at instant Speed is going to feel real good.
5 mana for a reanimate spell may seem like a big investment, but this thing can bring back an Artifact, Enchantment, or a Planeswalker. It's the only unrestricted spell that can reanimate a planeswalker that I can think of as the others have limitations (3 or less, or you have to pay into X, etc). While the sorcery speed definitely knocks it down a little, being able to bring back a lost planeswalker, a dangerous artifact or enchantment (perhaps one with a huge mana cost that you've milled or discarded) makes this card great in any deck that can abuse it. And it even gives you a powerstone to ramp your mana up.