Commander is a format built around a mana curve. Being able to play a spell each turn that increases your chance of victory is how you lead a winning strategy. Spells that are four mana start to really shape how you plan on playing the rest of the game. A four-mana spell should be impactful enough in the moment to push you towards victory. Here is a list of some of those cards in certain color combinations.

Xenagos, the Reveler

Xenagos, the Reveler is the first card on the list. Xenagos is a Planeswalker that can give you a huge burst of mana thanks to his +1 ability. This mana can be used to cast another spell immediately after Xenagos, almost making him feel free to play. His 0 ability provides a nice blocker. Xenagos's ultimate Planeswalker ability could win you the game if your deck is full of game ending threats. His +1 ability is mainly where this card shines, but all of his abilities feel relevant. A Planeswalker that can acrew immediate value on the turn it hits the battlefield is best, since they are the easiest to remove in a multiplayer setting.

Bell Borca, Spectral Sergeant

Bell Borca, Spectral Sergeant, is a four-mana Boros legend that gives you an extra card to cast each turn he remains in play. At the beginning of your upkeep, Bell Borca will put a card into exile, which you have the opportunity to play. This effect is similar to a card like Visions of Phyrexia, but with the upside of having a decent sized creature in play. Bell Borca's power is going to be equal to the mana value of the card we exile each turn. This could be zero if you hit a land, or it could be as high as nine if you hit a Blasphemous Act. Bell Borca also plays well into cards that care about casting spells out of exile, such as Passionate Archeologist. Bell Borca is a legendary creature so he fits right alongside Boros's legend sub theme that it leans into from time to time. I believe Bell Borca is an underutilized card when it comes to card advantage in Boros.

Ishai, Ojutai Dragonspeaker

Ishai, Ojutai Dragonspeaker is an absolutely terrifying card when you are on the receiving end of it. Ishai grows in power for each spell your opponent's cast. Believe it or not, your opponents are going to most likely be playing multiple spells a turn throughout the game, making Ishai a huge threat if left unchecked. Ishai is also blessed with having the keyword flying, making him even more scary. Ishai is a perfect target for the Command Zone for Azorius players, but also a decent threat to just include in the 99 most of the time. This card will start to eliminate players if not dealt with in a few turns. It shouldn't be a surprise to see it on a list of impactful spells for only four mana.

Duskmantle Seer

Duskmantle Seer is a very rare card to see in the Dimir color combination and I think it is great! Duskmantle Seer will punish your opponents for playing high mana valued cards and reward you for playing low to the ground threats. Dark Confidant sees very little play nowadays, especially with the release of Keen Duelist which does a similar thing. Duskmantle Seer is a slight variation on those card designs by giving each player a card and each player losing life. Wound Reflection is a great card to include in a deck with such cards as Duskmantle Seer and Sygg, River Cutthroat is a great Commander to add all of these cards into. Duskmantle Seer is also a vampire, even in Dimir there is a lot of support for that creature type. Definitely take the time to test out this card in your next Dimir brew.

Tadeas, Juniper Ascendant

Tadeas, Juniper Ascendant is a card draw engine on a body in Selesnya. It reminds me of a Toski, Bearer of Secrets effect melded with Professional Facebreaker. Tadeas has the added benefit of being super evasive to almost guarantee you to get at least one draw off him a turn. Tadeas is great for go wide creature decks that consistently play creatures every single turn. As soon as this card hits play, you have the opportunity to draw three cards at most. Having a consistent draw engine in a deck that can reliably drop creature threats is a key strategy to winning in most casual Commander games!

I hope you enjoyed reading through these multicolored cards that help fill in the four mana slots in your Commander's mana curve. All of these will push you one step closer to victory, so consider them the next time you are building a new Commander deck focused around one or two of these color combinations!

See you on the battlefield!

-Nigel