The deck I am playing this week truly is built around a single card, and that is Feather, the Redeemed. Feather, the Redeemed is such a powerful card once you can abuse it that building around it is actually worth it. Also, there happen to be other synergistic creatures and spells in the format to go alongside it, which leads to a really cool deck. Dreadhorde Arcanist and Tenth District Legionnaire are also creatures that are only going to be good in a very specific type of deck.
The list isn't stock. Most versions of W/R Feather have Legion Warboss in the sideboard, but I like that card enough to play it maindeck. I wouldn't recommend splashing another color in this deck. Playing a card like Dive Down isn't worth the manabase sacrifice in my opinion. As far as the spells are concerned I have liked this configuration. There will be matchups where Sheltering Light looks pretty bad, so it gets sided out a fair bit.
There are going to be other times where the burn looks bad, if the opponent is playing a dedicated control deck. On the surface the sideboard may look kind of underwhelming, but it really is built to have something to bring in for every matchup. Even against Nexus decks Demystify is pretty much the best sideboard card you can play in this color combination. Tocatli Honor Guard is going to be nice against a variety of green creature strategies with enters-the-battlefield effects, as well as Mono-Red Aggro.
Moving forward I believe that Boros Feather is powerful enough to be a contender in this metagame. What it is capable of is really powerful, once it gets its synergy going, or it can be a straight-up Boros beatdown deck. The worst matchups tend to be those with a ton of removal spells (though they are still winnable). You need to get a threat going in order to win. When I saw this deck originally I dismissed it, thinking it would be too underpowered based on the cards it plays. After actually playing with it I feel differently.
Connect: Twitch Twitter Instagram