ILLUNA, APEX OF WISHES
PRIMER
The gameplan here is simple, we will use the Mutate ability on Illuna, Apex of Wishes to cheat Omniscience into play. From there, winning is easy, with a plethora of powerful draw spell, extra turn effects, and zombie tokens.
You might ask, how can you be so sure you'll hit Omniscience with the Illuna trigger? Simple, it's the only nonland permanent in the deck! We will use instants, sorceries, and lands to generate tokens and ramp us to the requisite six mana. The deck is also packing a suite of cheap counterspells to protect our combo from pesky opponents attempting to interact at instant speed
Of course, Illuna *does* exile all the cards in the deck above Omniscience, so this author recommends that you get good and locate Omni near the top of your deck.
GENERATING TOKENS
A core element of the deck is that we need to create a non-human token to mutate Illuna onto. Even better if we can make a token at instant speed or on the same turn that we cast Illuna for it's mutate cost. Some of the key cards for achieving this are:
Field of the Dead - This card is absolutely critical to the deck. It serves as an alternate win-condition but most importantly demands the opponent to always have an instant speed answer to a token available or face down an Omniscience. In a similar vein Scapeshift allows us to generate an army of zombies to overwhelm the opponent. There are also some more creatures hiding in the manabase, with Blinkmoth Nexus and Gnotvold Slumbermound.
Lazotep Plating is another nice card in this deck as it doubles as being able to make a token on the opponent's turn AND to protect our own tokens against instant speed removal.
Other notable token makers are Swan Song, Emergent Sequence, Inscription of Insight, Experimental Overload, Commence the Endgame (instant speed!), and Alrund's Epiphany.
COMBO-ING OFF
Once we manage to get the Omniscience in play, it's time for the fun stuff. The idea is we can use extra turn spells to accelerate our creatures into combat and chunk down the opponent's life-total with our beefy flying commander and a bunch of tokens. The deck plays Time Warp, Karn's Temporal Sundering, and Alrund's Epiphany
Besides taking extra turns, the other part of combo-ing off is usually drawing a lot of cards (so we can do the Time Warp again). In particular Sea Gate Restoration and Overflowing Insight allow us to completely reload and usually fine the cards to win. Another notable card is Commit//Memory which gives us a fresh hand of seven cards when cast for its aftermath cost. Eureka Moment, Spring//Mind, Inscription of Insight, Brainstorm and others also allow the cards to keep a-flowing.
Finally, we have a few effects that let us rebuy draw-spells or Time Warp from the graveyard to continue combo-ing off. Bala-Ged Recovery and Experimental Overload can buy back any spell in the deck.
RAMP
Typically Unfriendly Brawl is a format where combo decks want to win on turn 4 or 5 if possible, otherwise you may be pre-empted by faster strategies. In order to assemble our combo quickly, we use spell/land based ramp.
When playing the deck, you typically want to mulligan into some of the cheap ramp spells, especially the two mana ones: Emergent Sqequence, Growth Spiral, and Explore.
In the three mana slot, we add Cultivate, Roiling Regrowth, and Spring to Mind. Roiling Regrowth is notable for it's ability to put lands into play at instant speed which can be useful with Field of the Dead. At 4 mana, we have Migration Path and Eureka Moment.
Perhaps one of the most powerful cards in the deck is Hour of Promise. This card allows you to tutor for Field of the Dead and even usually immediately makes 2 zombies (or 4 if you have all your deserts in play!)
DEFENDING YOURSELF
One weakness of this deck is that generally the combo is somewhat fragile (if we lose omni we have a hard time winning) and that there exist some faster combo decks out there. But, hey, Illuna conveniently has blue mana in the casting cost, so we are covered!
Counterspells - This deck plays several counterspells to both slow down the opponent's gameplan and to protect our own. Generally speaking we prioritize extremely cheap counters to allow us to attempt Illuna with counterspell backup. Notably, Swan Song, Spell Pierce, and Pact of Negation allow us to defend our combo for one or zero mana. Pact is especially cool because we can easily pay the cost once we have Omniscience in play.
In addition to these super cheap counterspells, we also play Negate, Disallow, Jwari Disruption, Supreme Will, Commit//Memory and Sublime Epiphany to counter hostile shenanigans. Notably, these more flexible counters become especially good after we have Omniscience in play.
Finally, we employ a few other interactive spells, namely Lightning Bolt, Fire Prophecy, and River's Rebuke to help control pesky permanents.
SO... WHAT IF I'M UNLUCKY?
As with any deck, this one has an achilles heel. Sometimes, you draw the Omniscience, sometimes it's just too deep in the library for you win even if you succeed in getting it into play. Well, as Bob might say, Greatness at Any Cost. Sometimes, the deck just decides it's not going to cooperate.
That said, we do play several tools to try to mitigate the drawback of drawing Omniscience. Namely, Commit//Memory, Brainstorm, Valakut Awakening, and Fire Prophecy all have abilities that allow us to put Omniscience back in the library. Be aware, that if you intentionally put Omni on the bottom of your library, that you will want to shuffle before executing the combo.
And hey, there's always the hardcast Omniscience plan! (And when that fails you can use Illuna's secret mode: giant flyer!)
CONCLUSION
The Illuna deck is one of the most interesting and rewarding decks in the format. It requires you to play very technically and is rewarding to good play. It's also just a great time to start combo-ing off and watch the life drain from your opponent's eyes.
I hope you enjoy the deck as much as I have!