Union Arena Re:ZERO Rem Deck Guide: Yellow Build 2026

TL;DR: Start with a Yellow Rem/Ram shell built around the four-energy Rem Raid, the five-energy Rem Snipe Raid, Ram's top-three search, and the Demon Sisters and Demon Power Events. Public list volume makes Rem the first test candidate, not a confirmed best deck: it's the focal character of more hosted UE24BT lists than anyone else, and Bandai's Top-Placing archive still has no Re:ZERO result.

Updated October 21, 2026: we replaced the September list snapshot with the current Union Arena Decklists counts, re-checked every card's text on Bandai's card list and the Top-Placing archive, and fixed the 50-card framework, which didn't add up to 50.

Union Arena Re:ZERO Rem deck guide: quick answer

The practical answer is a Yellow Rem/Ram Raid deck, but do not call Rem an official leader. Union Arena does not use the same leader-zone structure as One Piece TCG. Public decklist pages instead group lists around the character card that defines the shell, which is why the article uses Rem as the deck name.

The reason to start here is simple: representation. On October 21, 2026, Union Arena Decklists counted 935 hosted 50-card lists that play at least one UE24BT card, and Rem was the focal character of 37% of them, with Emilia at 33%. Its Rem page holds 258 Yellow Rem lists, the newest from October 16. Those figures measure shared list volume, not wins, conversion rate, or card availability. The site's tier label is a community label, not a Bandai tier.

The official Bandai Re:ZERO product page confirms the UE24BT booster released in English on September 18, 2026. Bandai's Top-Placing Decks archive, checked again on October 21, has no Re:ZERO deck yet; its newest results were posted September 18. This guide gives you a useful first draft and a testing method, not an invented S-tier verdict.

Why Rem is the first Re:ZERO build to test

Rem's public sample is large enough to reveal repeated card choices, and the Yellow cards in the public Rem/Ram list give the deck a recognizable plan. The specific public list checked here is a 50-card ExBurst list dated September 10, not an event-winning list. It repeats the Rem Raid cards, the Ram search and Raid package, and Yellow Events that reward having Rem on the field.

The timing matters: that list is dated before the wide release. Public lists show what players are building, while the official archive tells us whether a build has been reported as a top finisher. Until we have both, call it a first test rather than the best deck.

If you'd rather see the shell laid out card by card, Dplaystcgs posted a Yellow Rem/Ram deck profile on October 17:

Union Arena Re:ZERO Rem deck guide: core Raid engine

Begin with a low-cost base that can become a Raid target. The Yellow base Rem UE24BT/REZ-1-013 UE24BT-013UE24BT-013Shop on TCGplayer is a zero-energy, 1500 BP Character with Nullify Impact. The starter deck also supplies Rem UE24ST/REZ-1-103 UE24ST-103UE24ST-103Shop on TCGplayer, a zero-energy base with 2000 BP. They do not replace the Raid cards, but they give the deck cheap bodies and more ways to have a Rem available before the four-energy turn.

The first major payoff is Rem UE24BT/REZ-1-019 UE24BT-019UE24BT-019Shop on TCGplayer. It is a four-energy, 4000 BP Yellow Raid Character. When it enters, it can play a Yellow Ram or Rem card costing three or less with one AP from your hand onto the field in the resting position. Its front-line Activate: Main ability can give a Ram or another Rem Impact (1) once per turn. This is a setup turn, not a free extra attack: you still pay the AP cost for the Raid and the played card.

Image: Bandai, UNION ARENA official card list (UE24BT/REZ-1-019). Her Raid line develops a resting Yellow Ram or Rem, and her front-line ability supplies Impact (1).

At five energy, Rem UE24BT/REZ-1-020 UE24BT-020UE24BT-020Shop on TCGplayer changes the question from development to pressure. Its Raid returns Rem to active and lets her move to the front line. If none of your field Characters have affinities, she gains Impact (1) for the turn. Her once-per-turn Activate: Main ability grants Snipe, so she may attack an opposing front-line Character without allowing a block, but the printed restriction means she cannot use Snipe to target a Character at 4000 BP or higher. After the Raid, the base card is placed into your sideline.

The two Rem Raids therefore do different jobs. The four-energy version turns a hand card into board development and can make another family card hit harder. The five-energy version is a cleaner way to attack a smaller opposing Character while preserving the option to turn the Raid into a direct pressure turn. Do not treat either one as universal removal.

The Ram package makes the Yellow shell consistent

The early selection piece is Ram UE24BT/REZ-1-009 UE24BT-009UE24BT-009Shop on TCGplayer, a one-energy, 2000 BP Character. Its When Played effect looks at the top three cards for an eligible Ram, Rem, or Roswaal L Mathers card and adds one to hand, then places a hand card into your sideline if the search succeeds. That last clause is part of the plan, not a drawback to ignore: the sideline can hold cards that later effects use, while the search keeps the Raid curve moving.

The public list also uses Roswaal L Mathers UE24BT/REZ-1-021 UE24BT-021UE24BT-021Shop on TCGplayer as a Yellow support option. Its ability needs Ram and Rem on your field, then draws a card and places one card from hand into your sideline. That makes it a payoff for developing both sides of the package, not a card you want to play before the field has the required names.

The four-energy Ram UE24BT/REZ-1-011 UE24BT-011UE24BT-011Shop on TCGplayer is the defensive Raid. It returns Ram to active and may move her to the front line. If an opponent's ability would sideline a Rem on your field, Ram can be sidelined instead. Her When Played effect then chooses between reducing every opposing front-line Character at 1500 BP or more by 1000 for the turn, or reducing one Character at 2500 BP or more by 2000. The first mode is better for a wide board of medium bodies; the second is better when one blocker is preventing a clean attack.

Image: Bandai, UNION ARENA official card list (UE24BT/REZ-1-009, 011, 021), the three cards this section covers.

Events and the Rem condition

Demon Sisters UE24BT/REZ-1-030 UE24BT-030UE24BT-030Shop on TCGplayer is a three-energy Yellow Event that switches up to two of your AP cards to active. Its Final trigger restores the top card of your deck to your Life area when you have zero Life. That makes it a flexible mid-game AP reset and a live late-game trigger, but it is not a reason to fill the deck with Events before the Character curve works.

Demon Power UE24BT/REZ-1-031 UE24BT-031UE24BT-031Shop on TCGplayer costs four energy and one AP. It sidelines an opposing front-line Character at 3000 BP or less, or at 5000 BP or less if Rem is on your field. Its Special trigger sidelines an opposing front-line Character. The five-thousand threshold is the real reason to keep a Rem body in play before spending it, but the Event still asks for an AP and should not be described as unconditional removal.

Together, the Events pull the list in two directions. Demon Sisters helps you reuse AP for another Raid or Event, while Demon Power turns Rem's presence into a wider sideline range. Start with the counts visible in public Yellow lists, then adjust after tracking whether your hand has enough Characters to establish the condition. Standard construction also limits the total number of Special, Color, and Final trigger cards to four each, so count the trigger families after adding other support.

Starting 50-card framework

The table is a testing framework, not a copied tournament list. The public Rem/Ram list is a useful reference, but its visible dates predate the wide release and do not include match records. Use the official card list to verify every swap before registering the deck.

That framework leaves room to test a lower curve or more Events without pretending the current public sample proves one ratio. If your list cannot produce a playable early Character, the five-energy Rem Raid will arrive without enough board context. If it floods on top end, trim the expensive copies before cutting the one-energy search.

Step-by-Step: Piloting the Yellow Rem/Ram build

1. Keep the source material together. Standard Union Arena construction uses one source material or title. Re:ZERO lets you choose among colors within that title, but mixing in cards from another anime is not a default option. Check the event rules before changing the format.

2. Mulligan for an early body and a path to four energy. A low-cost Rem or Ram, Ram's top-three search, and a four-energy Rem Raid form a useful starting pattern. Do not keep a hand full of five-energy finishers just because Rem 020 is the flashy card. This is a testing heuristic based on the printed curve, not a published matchup result.

3. Use Ram to prepare the sideline. Ram 009 searches the top three and then files a hand card if it finds a target. Choose a card you can afford to lose, while keeping the Rem Raid or the next curve piece in hand. Roswaal's draw line becomes better after both names are actually on the field.

4. Raid Rem 019 when development matters. At four energy, use the Raid to put a Yellow Ram or Rem from hand onto the field resting. Plan the next turn before choosing the free body, because the played card is not immediately active. If the front-line Activate: Main is available, use Impact on the attacker that can create the best trade rather than adding it automatically to the largest body.

5. Protect the condition before playing Events. Keep a Rem on the field when Demon Power needs its 5000 BP threshold. If the opponent's effect threatens that Rem, Ram 011 can convert the removal attempt into a Ram sideline instead. This is a timing decision, not a blanket rule to hold every Ram in hand.

6. Use Rem 020 as a targeted pressure turn. Snipe is strongest against a smaller front-line Character that blocks your normal attack or carries an important setup effect. Because the printed restriction excludes targets at 4000 BP or higher, do not spend the turn assuming it answers every large body. The base card going to the sideline also means the Raid can leave useful material for later effects, but it does not create a second free Rem.

7. Record games by line, not by feeling. After each game, mark whether you missed a Rem base, failed to reach four or five energy, lacked an AP, or had the wrong target for Snipe. The result tells you which ratio to change. A public list count cannot answer those questions for your local room.

Common mistakes with the Rem build

• Calling Rem an official leader: use Rem as the focal card name, but do not describe a leader zone that the game does not use.
• Treating public list volume as a win rate: the biggest list share shows representation, not a win rate or a tournament conversion rate.
• Playing Rem 019 for value without planning the resting body: its hand deployment develops the board, but the new Character is not immediately active.
• Using Rem 020 Snipe on a 4000 BP target: the printed text explicitly restricts that target range.
• Spending Demon Power before checking for Rem: without Rem on the field, its sideline ceiling is 3000 BP rather than 5000 BP.
• Filling the list with only Raid cards: the deck still needs cheap bases, AP management, and enough early energy generation to reach the Raid turns.

What would make this recommendation stronger

The current recommendation is deliberately narrow. Rem leads the public UE24BT list-volume snapshot, and the Yellow Rem/Ram sample has a clear card plan, but neither fact is a tournament result. A stronger recommendation would require a named event, a final record, and a full decklist from the official results archive or a clearly identified event source.

When those results appear, compare Rem with Emilia and the Blue Rem/Subaru builds rather than simply replacing the current paragraph with a new tier label. Look for repeated top-end cards, whether the winning list uses the Yellow Rem/Ram shell, and whether the result came from a constructed Standard event rather than a Five Pack Battle release event. That keeps the article useful after launch without turning an early snapshot into permanent certainty.

Our take

Build Yellow Rem/Ram first if you're starting Re:ZERO. It's the shell most players are testing, so you'll find the most lists to compare against, and Rem 019 plus Ram 011 give it a plan you can learn in a few games. Don't call it the best deck yet: until Bandai posts a Re:ZERO result, all anyone has is list volume.

Key Takeaways

• Rem is the first Re:ZERO build to test because it's the most-built shell in public lists, not because a tournament has proven it best.
• The Yellow plan pairs Rem 019's board development with Rem 020's targeted Snipe pressure.
• Ram 009 searches the family and files a hand card to the sideline, while Ram 011 protects Rem and changes BP math.
• Demon Sisters recovers up to two AP cards, and Demon Power reaches 5000 BP when Rem is on the field.
• The public evidence was checked before post-launch constructed results were available, so update the guide when full event records appear.

Frequently Asked Questions

Is Rem the strongest Re:ZERO build?

Rem is the first test candidate by public representation: more hosted UE24BT lists are built around her than around Emilia or anyone else. That doesn't prove a higher win rate than Emilia, Beatrice, or another build.

Does Union Arena Re:ZERO have a leader card?

This deck does not use a formal leader zone. Public pages group lists around a focal Character card, so "Rem build" is a practical deck label rather than a statement that Rem is a leader card.

Which Rem color should I build first?

Start with Yellow if you want to reproduce the public Rem/Ram sample used in this guide. Blue Rem/Subaru is a separate test direction, not a sideboard swap, so compare it as its own shell.

What does Rem 019 do?

The four-energy Yellow Raid Rem can play a Yellow Ram or Rem costing three or less from hand to the field resting, then its front-line once-per-turn ability can give a Ram or another Rem Impact (1).

What does Rem 020 do?

The five-energy Raid Rem can gain Impact (1) when your field has no affinities and can gain Snipe for a targeted attack. Its Snipe cannot target a Character at 4000 BP or higher, and the Raided base goes to your sideline.

Has this deck won a post-launch event?

No. Bandai's Top-Placing archive had no Re:ZERO deck when we checked on October 21, 2026. Treat the current list as a test shell until a full result is available.

Related Reading

• Union Arena Re:ZERO EN Tier List: 7-Leader Snapshot: The evidence snapshot that puts Rem first by public-list representation.
• Union Arena Re:ZERO Prerelease and Release Date: Release facts and the starter deck context.
• Union Arena Re:ZERO Buying Guide: Box, Deck, or Singles: Compare the starter, sealed product, and singles before buying into the build.
• Union Arena Re:ZERO Emilia Deck Guide: Purple Build 2026: Compare the Purple Emilia and Echidna shell with this Yellow Rem/Ram test build.
• Union Arena Deck Building Guide: Build a 50-Card Deck: Main-deck, AP, energy, and source-material construction rules.
• Union Arena Raid Mechanic Explained: Transform Your Cards: How the Raid timing used by Rem and Ram works.
• Union Arena EN Meta Tier List 2026: Broader format evidence with official results kept separate from list volume.
• All Union Arena Sets: Complete EN Release Schedule (2026): Re:ZERO's place in the English release calendar.

Correction, October 21, 2026: the 50-card framework used to give a range of "other support" cards that left the deck short of 50. That row now says the rest of the 50.

References

• Bandai official Re:ZERO UE24BT product page: release date, set configuration, and product facts.
• Bandai official Union Arena card list: live card database used to verify names, colors, types, costs, and effects.
• Bandai official Rem UE24BT/REZ-1-019 card entry: four-energy Raid text.
• Bandai official Rem UE24BT/REZ-1-020 card entry: five-energy Raid, Impact, and Snipe text.
• Bandai official Ram UE24BT/REZ-1-009 card entry: top-three search and sideline text.
• Bandai official Ram UE24BT/REZ-1-011 card entry: Rem protection and BP-reduction modes.
• Union Arena Decklists Rem/Ram public list: dated 50-card public list used as a shell reference, not tournament evidence.
• Union Arena Decklists homepage: UE24BT list share by focal character, checked October 21, 2026.
• Union Arena Decklists Rem page: Yellow Rem list count and newest list date.
• Bandai official Top-Placing Decks archive: results page checked for a verified Re:ZERO constructed placement.
• Bandai official Union Arena rule manual: deck construction, AP, and format rules.