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Shonen TCG · General
Union Arena JJK Guide: Jujutsu Kaisen Best Decks (2026)
13 min readBy Michael Riley
Tagsunion-arenajujutsu-kaisendeck-guidedomain-expansion
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Shonen TCG · General
Reviewing
Union Arena
JJK is the Union Arena set that separates experienced players from new ones. Not because the rules are complicated, but because Domain Expansion punishes misplay at a rate no other Union Arena IP does. When your board wipe also kills all your own characters if you build the deck wrong, every decision carries higher stakes.
The payoff: Gojo Control is the most satisfying deck I play in Union Arena. Surviving until the Domain Expansion window, playing it with perfect setup, watching every non-Cursed character K.O. simultaneously while your board remains untouched. That moment does not get old.
TL;DR: Union Arena JJK (BT03) uses Domain Expansion (5-cost board wipe, K.O.'s all non-Cursed Energy characters) as the primary game-changer. Gojo Control is the top build at 55-57% win rate. Main weakness: Solo Leveling's Shadows survive Domain Expansion and refuel their engine. Competitive cost $120-160.
JJK decks run almost exclusively Cursed Energy characters so that Domain Expansion does not K.O. your own board when resolved. Gojo and Itadori serve as your finishers; Megumi, Nobara, and Nanami fill the Cursed Energy character slots. Domain Expansion resolves around turn 5-6 when your opponent has over-extended into what they think is a favorable board position.
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TCG Deck Analyst
Former card game tournament organiser turned analyst. Covers One Piece TCG meta, deck efficiency, and card valuation. Builds spreadsheets for decks most people just play.
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General · 13 min
Domain Expansion's text reads: "K.O. all characters on the field that do not have the Cursed Energy trait. Draw 1 card."
At 5 energy, this is expensive. Running it requires a deck specifically built to survive it. Every character in a JJK deck needs the Cursed Energy trait, or they die to their own event.
Here's why it is still one of the best events in Union Arena:
Timing asymmetry: Your opponent does not know exactly when you will play Domain Expansion. They over-extend into a board they expect to have, then lose it all at once.
Selective wipe: Most board wipes in TCGs hit everyone equally. Domain Expansion is one-sided. Your side is untouched; theirs is gone.
Draw: The extra card replaces itself, making it cost-neutral in card advantage while gaining board advantage.
Twice per game: You typically run 3-4 copies. Against midrange opponents, two resolutions are enough to win the game entirely.
The counterplay is running Cursed Energy characters yourself (JJK mirror) or playing around the timing (keep characters alive rather than overextending). Against opponents who do not know the matchup, Domain Expansion wins 70%+ of games by itself.
Key Card: Gojo Satoru
Cursed Energy Core (24 cards):
Finishers (6 cards):
Events (20 cards):
Total: 50 cards
GODEEPER: New to Union Arena and wondering how JJK fits compared to other IPs? The beginner guide explains the base rules and compares the IPs. Union Arena TCG Beginner Guide →
Replace Gojo Full Power (8-cost) with 2x additional Itadori and run Divergent Fist at 4 copies as a primary removal piece rather than a supplemental event. Itadori Aggro wins faster but is more vulnerable to early blockers and has less board-clearing power outside of Domain Expansion.
Itadori Aggro is better in metas with fast aggro decks. Gojo Control is better in metas with midrange and attrition decks. Current EN meta leans midrange, making Gojo Control the default recommendation.
Gojo Satoru (Special Rare, $30-45): The deck's best closer. Nullification ability means he cannot be targeted by events costing 3 or less, removing most opponent removal from equation. 9000 power beats all but the largest opposing bodies. Run 2 copies.
Domain Expansion (4 copies, uncommon rarity, $1-2 each): The defining card. Cheap to acquire. Do not cut below 4 copies regardless of budget.
Nanami (4-cost version, $3-6): Nanami's attack-through-blocker ability matters more than his power stat. JJK's best board states involve clearing a Domain Expansion window and then attacking through any remaining blockers with Nanami on follow-up.
Black Flash (counter event, $2-4): +3000 counter for Cursed characters is the best defensive event in the set. Keeps Gojo alive against high-power attacks. Run 4 copies.
Ryomen Sukuna (Special Rare, $20-30): Secondary finisher that pairs with Domain Expansion. Play Domain Expansion, then Sukuna attacks 4 times against the cleared board. The 4-attack sequence is the fastest close sequence in Union Arena.
Keep:
Mulligan:
The deck's worst opening is Gojo + Sukuna + Gojo Full Power. These are all late-game cards; playing them early without early board presence means you are behind by turn 4 with no way to catch up before your Domain Expansion window.
Turn 1-2: Establish Cursed Energy characters. Nobara at 2-cost, Itadori or Megumi at 3-cost.
Turn 3-4: Continue filling the board with Cursed Energy characters. Nanami at 4-cost starts applying pressure. Hold Domain Expansion in hand.
Turn 5: Domain Expansion. Your opponent should have 3-5 characters on field. Your characters all survive. Their field clears. Attack into the empty board for maximum damage.
Turn 6: Play Gojo or Sukuna. Follow up Domain Expansion's board clear with a finisher. Gojo holds position at 9000+ power; Sukuna chains 4 attacks.
Turn 7+: Close. Two turns of attack with Gojo plus leader damage finishes most games after a successful Domain Expansion.
vs. Solo Leveling (40-60, unfavorable): Domain Expansion sends Shadows to Shadow Storage rather than the discard pile. Jinwoo immediately summons them back. Your board wipe becomes free setup for their engine. This matchup is JJK's hardest in the format.
vs. Bleach (60-40, favorable): Domain Expansion removes all of Bleach's Soul Reapers simultaneously, resetting Hollow Form progress to zero. Bleach's best counter is rebuilding 3 Soul Reapers before a second Domain Expansion, which the 4x Domain Expansion count makes difficult.
vs. Dragon Ball Super (58-42, favorable): DBZ's power scaling requires characters on field to accumulate Ki. Domain Expansion resets their entire Ki investment. JJK has enough early pressure to close before DBZ rebuilds.
vs. InuYasha (50-50, even): InuYasha's Jewel Shard counters sit on characters; Domain Expansion K.O.'s those characters and removes all counters simultaneously. JJK wins the mid-game. InuYasha wins if they rebuild counters before Domain Expansion resolves again.
vs. JJK mirror (50-50): Both players run Domain Expansion at 4 copies. The player who resolves Domain Expansion into a more developed board wins. Both players play around the timing. Skill-intensive mirror match.
Budget JJK ($70-90): Replace 2x Gojo Satoru and 2x Ryomen Sukuna with 4x Itadori Yuji (Rare, $3-5 each). The deck loses its top-end finishers but Domain Expansion itself is inexpensive, and the core engine runs the same. Competitive at locals, not recommended for regionals.
Announce Domain Expansion at the right moment. Do not play it when your opponent has 1-2 characters. Wait until they have 4-5 characters and have over-committed. The tempo gain is proportional to board size when Domain Expansion resolves.
Against Solo Leveling specifically, consider siding into a faster aggro plan post-board. Domain Expansion against Solo Leveling generates no advantage; you need to close before their engine generates overwhelming resource advantage.
Read your Domain Expansion carefully. Some versions say "K.O. all characters that do not have Cursed Energy trait." Some say "that are not Cursed Energy." These are functionally identical but confirm the trait name match before assuming something survives.
Does Domain Expansion hit the opponent's Key Card? No. Domain Expansion only affects characters on the field. The Key Card is in a separate zone and is not affected.
Can you chain two Domain Expansions in one turn? Yes, if you have the energy. Playing Domain Expansion twice in one turn at 5+5=10 energy requires a very late-game board state. Possible but uncommon. Usually the second Domain Expansion is saved for the following turn.
What if both players have only Cursed Energy characters? Domain Expansion K.O.'s no characters. You spent 5 energy for 1 card draw. This is the downside of the Domain Expansion mirror: both players' characters survive.
Is JJK good for tournament play long-term? Yes. JJK's mechanics are complex enough that they will remain competitively viable as long as the set is in standard. Skill-intensive decks tend to have longer competitive lives because experienced pilots consistently outperform average play.
Where can I find JJK Union Arena singles at fair prices? TCGPlayer for US buyers, CardMarket for European buyers. Domain Expansion is cheap ($1-2); Gojo Satoru is the main expense. Buy Gojo first before building the rest of the deck.
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