Last weekend saw the first MagicFest Online Weekly Championship since the release of Ikoria: Lair of Behemoths. This invitation-only MTG Arena event featured the MPL, members of the Rivals League, and players who had earned enough wins in the Daily Qualifiers. Over two days of competition, they battled with their best Standard decks for their share of a $25,000 prize pool.

In total, 466 Standard decklists were registered for the event, and companions made quite an impact. The following table contains the metagame breakdown for Day 1 (all 466 players) and for Day 2 (the top 128 players after Swiss rounds on Day 1). Each archetype name links to the highest-placing decklist of that type.

The top three companions were as follows:

• 23.4% of the Day 1 field had Keruga, the Macrosage as their companion.
• 22.3% of the Day 1 field had Yorion, Sky Nomad as their companion.
• 10.9% of the Day 1 field had Lurrus of the Dream-Den as their companion.

Most-Played Deck: Jeskai Fires with Keruga

Jeskai Fires was already one of the stronger decks before the release of Ikoria: Lair of Behemoths, and it's gotten even stronger. Like before, it still plans to exploit Fires of Invention to cast Cavalier of Flame or Kenrith, the Returned King on turn five, with mana up to activate their abilities right away.

The most important addition from Ikoria: Lair of Behemoths is Keruga, the Macrosage. For Jeskai Fires, Keruga's deck building restriction is extremely easy to satisfy, especially since Brazen Borrower and Bonecrusher Giant still enable on-curve plays on turn two. Losing Aether Gust and Robber of the Rich as sideboard options is the price to pay for starting the game with a guaranteed five-drop that will draw you at least one card.

Kouhei K. finished sixth with the following list.

Note: 59 of the 108 Jeskai Fires players ran a Swamp for the activated ability of Kenrith, the Returned King and for Kunoros, Hound of Athreos from the sideboard. (Kunoros is brilliant against Lurrus of the Dream-Den decks in particular. While Grafdigger's Cage may be better again graveyard recursion, Keruga, the Macrosage as companion forbids that.)

Despite this minor black splash, I still classified these decks as "Jeskai Fires" within the metagame breakdown.

The Second-Most Popular Companion: Yorion, Sky Nomad

Many players chose to play 80-card Yorion, Sky Nomad decks. The most popular variant was based on the interaction between Yorion and Fires of Invention: If you control Fires of Invention on turn five, then you can cast Yorion as your second spell, exile Fires of Invention, and then use your mana to play another spell (your third for the turn) because Fires is no longer on the battlefield. This allows you to cast up to 15 mana worth of spells on turn five, which is obviously good.

Yorion Fires decks were commonly four-color builds (skipping black spells), but they had a poor Day 2 conversion rate and no one finished higher than 74th.

More success was had by players who slotted Yorion, Sky Nomad into an existing archetype, most commonly Bant Ramp or Azorius Control. These "good stuff" decks are not based around a deck-defining engine card (such as Fires of Invention or Wilderness Reclamation) and prior to the release of Ikoria: Lair of Behemoths they included many three-ofs. Hence, they could easily reach Yorion's companion requirement of 80 cards by turning their three-ofs into four-ofs without weakening their average card quality too much.

Adding 20 cards to a deck still comes with a cost, for example to the mana base (as you're limited to 4 copies of key dual lands) and to the sideboard (as you'll draw key sideboard cards less frequently). But starting with an eighth card, even one that isn't itself game-defining, is a large benefit that outweighs the sacrifice in consistency for those decks.

MPL player Piotr Głogowski finished third with the following list. In this deck, Yorion, Sky Nomad's blink ability is not essential, but it can generate value by resetting Elspeth Conquers Death or a planeswalker. Players are also more widely adopting Omen of the Sea and Agent of Treachery to synergize with the companion.

Companions Unnecessary: Temur Reclamation

Players who did not include a companion most commonly gravitated towards Temur Reclamation and Sultai Ramp. Sure, some believers in Wilderness Reclamation or Casualties of War included Yorion, Sky Nomad as their companion—they are listed as a separate archetype in the metagame breakdown—but the vast majority went without a companion. They recognized that in decks based around a deck-defining engine or payoff card, sticking to 60 cards maximizes the probability of drawing the key card.

MPL player Seth Manfield finished second with the following list.

A Divided House: Rakdos Sacrifice

Rakdos Sacrifice was one of the stronger decks before the release of Ikoria: Lair of Behemoths, and it has cemented its position as the most popular aggro deck in the new Standard. (Mono-Red Aggro has unfortunately dropped off the metagame: no Mono-Red players advanced to Day 2.)

Like before, the sacrifice engine revolves around Cauldron Familiar, Witch's Oven, and Claim the Firstborn. Serrated Scorpion from Ikoria: Lair of Behemoths now slots right in as a synergistic one-drop.

The main question for Rakdos Sacrifice players was: Do you use Lurrus of the Dream-Den, Obosh, the Prepiercer, or no companion at all?

• 6.0% of the field used Lurrus of the Dream-Den as their companion in Rakdos Sacrifice. This unlocks Priest of Forgotten Gods and Dreadhorde Butcher while trading off Mayhem Devil and other cards with coverted mana costs greater than two.
• 4.5% of the field used Obosh, the Preypiercer as the companion in Rakdos Sacrifice. This unlocks Mayhem Devil and Woe Strider while preventing you from adding any cards, like Priest of Forgotten Gods, that are an even converted mana cost.
• 0.9% of the field wanted both two-drops and three-drops in their Rakdos Sacrifice build, so they eschewed a companion altogether.

Based on Day 2 conversion rates and final standings, the Obosh, the Preypiercer builds performed the best, so it appears that having access to Mayhem Devil is stronger. James R. won the Weekly Championship with the following list.

The Breakout Deck of the Weekend: Jeskai Cycling

It looks like a draft deck, but it's a real Standard contender. When you can run four copies of key uncommons like Flourishing Fox and Zenith Flare, the strategy is good enough for Standard. Cycling decks were 3.2% of the Day 1 metagame, and they did surprisingly well.

The distinction between Boros and Jeskai Cycling builds was whether the list included non-cycling blue cards, such as Improbable Alliance. Based on Day 2 conversion rates and final standings, Jeskai builds were more successful than Boros builds. Takumi U. finished 4th with the following list.

The five decklists that I provided in this article so far could be viewed as the set of "Decks To Beat" in Standard. If you want to get started in Daily Qualifiers or other Standard events, then all five would be great choices. Conversely, if you plan to brew up a new deck in Standard, then you need to have a general gameplay and sideboard plan against each of them.

The Other 12.7%

The "Other" category included some very spicy decks. It would be out of the scope of this article to list all decks, but I will provide the ones that made Day 2. Out of the 128 players in Day 2, 10 were on a deck that I put in the "Other" category:

• Four-Color Ramp (Yorion, Sky Nomad)
• Azorius Control
• Azorius Blink (Yorion, Sky Nomad)
• Simic Ramp
• Jeskai Superfriends (Zirda, the Dawnwaker)
• Gruul Aggro
• Jund Sacrifice (Jegantha, the Wellspring)
• Five-Color Niv (Yorion, Sky Nomad)
• Orzhov Sacrifice (Yorion, Sky Nomad)
• Jeskai Control (Kaheera, the Orphanguard or Keruga, the Macrosage)

The Most-Played Ikoria: Lair of Behemoths Card was Shark Typhoon

The ten most-played non-land cards among all main decks and sideboards break down as follows.

That's basically half a Fires of Invention deck, and only one Ikoria: Lair of Behemoths card: Shark Typhoon. This cycling spell has nicely slotted into a variety of decks, but it's been an important addition for Temur Reclamation in particular. Previously, this deck struggled against Teferi, Time Raveler, but Shark Typhoon elegantly solves that issue. As a result, Temur Reclamation has been reinvigorated.

In conclusion, Ikoria has had a huge impact on the competitive Standard landscape, and companions have shaken up the format. While this first Weekly Championship defined the best new Standard decks, the next question is how to beat them. Players who discover how to beat Jeskai Fires in particular will likely find success in the next Weekly Championship.

Watch the action unfold all week in 24/7 live coverage of MagicFest Online over at twitch.tv/channelfireball, and sign up for Daily Qualifiers and more at the MagicFest Online hub.