Combo · ENGINE

813.5.b plus 358.4: the Mystic Vortex taxes the ANSWER and never the opening play, because whoever closes the state needs only [Action] and 813.1.b's containment runs one way

4 cards · body · verified

Pieces

• Mystic Vortex ×1 VEN-160 · battlefield

  During showdowns here, cards with [Reaction] cost 1 Power of any domain more to play. (Hidden cards have [Reaction].)

• Overt Operation ×3 OGN-153 · payoff · body

  [Action] (Play on your turn or in showdowns.) For each friendly unit, you may spend its buff to ready it. Then buff all friendly units. (Each one that doesn't have a buff gets a +1 Might buff.)

Payoff

Deck

• Overt Operation is mono-Body and the Mystic Vortex is Colorless, so 103.1.b needs only a legend carrying Body. Measured over data/cards.json on 2026-09-12 that is seventeen legend NAMES: Relentless Storm, Blind Monk, Bounty Hunter, The Boss, Wuju Bladesman - Starter, Might of Demacia - Starter, Purifier, Grandmaster at Arms, Battle Mistress, Grand Duelist, Pridestalker, Wuju Master, Voidreaver, Keeper of the Hammer, Butcher of the Sands, Defender of Tomorrow and Matriarch of War. One of those, the Wuju Bladesman starter legend, is the single restricted row in data/legality.json (2v2 only) - legal here, but capped in that format.
• Neither card is a Signature card (checked against data/cards.json) and neither appears in data/legality.json in any format - checked 2026-09-12.
• 485.4.a has each player provide three battlefields and 485.5 selects RANDOMLY, so the Vortex is not certain to be on the table; 103.4.c forbids a second copy of the name.
• You want to be the ATTACKER at this battlefield. 345 gives Focus to the player who applied Contested status and 464.2.c.1 makes that the Attacker, so on your own attack you act first - which is the whole of the asymmetry.

Run play

• the Vortex taxes whoever answers, and Focus changes hands

Prerequisites

• THE RULES ARE THREE PARAGRAPHS AND NONE OF THEM HAS EVER BEEN CITED HERE. 813.5 - 'Reaction is a referencable characteristic.' - with 813.5.a for a Game Object, 813.5.b for a Spell and 813.5.c for an Ability. All four are cited by no entry and no synergy rule in this project (measured 2026-09-12), and the Vortex is their only reader in the pool.
• THE ASYMMETRY IS PRINTED IN 358.4 AS TWO WORKED EXAMPLES, ONE FOR EACH SIDE. 'Check that the card has the appropriate permissions to be played at this timing. Example: If the state is Showdown Closed and the card was the one that Closed the state, ensure that it has [Action] or [Reaction]. Example: If the state is Closed and the card wasn't the one that Closed the state, ensure that it has [Reaction].' So the player who acts FIRST into a showdown needs only [Action]; the player who RESPONDS needs [Reaction]. The Vortex taxes [Reaction] and therefore taxes only the second of those. 358.4 is uncited, and 358.5 is the undo if the check fails.
• AND 813.1.b IS WHY AN [Action] CARD IS NOT QUIETLY A [Reaction] CARD. 'Reaction grants the corresponding card or effect all abilities and permissions of Action.' The containment runs ONE way: a [Reaction] card can do everything an [Action] card can, but an [Action] card does not have Reaction, so 813.5.b reads FALSE on Overt Operation and the Vortex has nothing to charge. This is the constructive use of a rule the catalogue already cites fifty times for the opposite purpose.
• THE ARITHMETIC, WITH THE QUANTITIES DECLARED. Attack into the Vortex. 345 and 464.2.c.1.a give you Focus (464.2.c.1.b is the case where they do not - see the notable), so you play Overt Operation first, closing the Showdown state: 5 Energy and 2 Body Power, and NOTHING more, because 358.4's first example admits an [Action] card and 813.5.b never fires. Your opponent's answer - any removal or trick they hold - must carry [Reaction] to be legal at all (358.4's second example) and pays one rainbow Power more than it says on the card. You have bought a rainbow off every answer to your own attack, on a battlefield that costs you a deck slot and no cards.
• WHAT OVERT OPERATION ACTUALLY DOES INSIDE THE SHOWDOWN, STATED HONESTLY. The ready half is nearly worthless there - 144.1.b forbids the Standard Move outside your Main Phase and combat does not read exhaustion - so what you are paying 5 Energy and 2 Power for is the second sentence: every friendly unit ends the resolution carrying a buff, which 703 fixes at +1 Might each, and 465.2.c reads current Might at assignment. It is a board-wide +1 delivered after the attackers are declared. The spend-then-rebuff wording is what makes it work on a board that is already buffed: 702.2.b removes the counter to pay for the ready and 702.3.a then allows a fresh one, where a bare mass buffer would place nothing on an already-buffed body.
• THE VORTEX TAXES CARDS, NOT ABILITIES - WHICH IS WHY 813.5.c EXISTS AND IS A SEPARATE SENTENCE. The Vortex says 'cards with [Reaction]'. An [Action] or [Reaction] ABILITY on a permanent is not a card being played, so it is never taxed: OGN-113 Malzahar, Fanatic ('Kill a friendly unit or gear, :rb_exhaust:: [Action] - [Add] :rb_rune_rainbow::rb_rune_rainbow:') pays the Vortex nothing, and neither does any of the eleven [Reaction][>] mana abilities in the pool. The rules keep the three cases apart on purpose at 813.5.a, 813.5.b and 813.5.c, and 135.2.e.7.b is the notation rule underneath it: 'Whatever instruction or ability comes after the [>] is modified by the keyword that comes before the [>]' - so a permissive keyword behind an arrow belongs to that ability alone and never to the card. That paragraph is also uncited.
• WHAT THE VORTEX DOES TAX, AND IT IS THE COST OF RUNNING IT. It names no player, so it charges you too whenever you are the one answering - and its parenthetical, 'Hidden cards have [Reaction]', is 811.6 ('A card that is Hidden gains Reaction while facedown or played from facedown') made explicit, so the Vortex is the ONE card in the pool that makes a [Hidden] play cost anything at all, against 811.1.b's 'ignoring its base cost'. A list running both the Vortex and a Hidden package is taxing itself.
• IT IS NOT THE SAME LINE AS mystic-vortex-helm-suppression-tax. That entry stacks the Vortex with VEN-045 Helm of Suppression, the pool's only asymmetric cost increase, and is about compounding a tax on the opponent generally. This entry is about the direction the Vortex's own tax runs inside a single showdown, which needs 358.4 and 813.1.b and has nothing to do with the Helm; the two compose and neither depends on the other.
• CITATION UPGRADE (2026-09-12, #191 batch 19): 813.1.d is the keyword-level corroboration of the notation argument this entry makes from 135.2.e.7.b — *"Reaction is formatted as [Reaction] on cards, or [Reaction][>] on abilities."* The Vortex taxes *cards* with Reaction, and that one sentence is why an ability carrying the keyword behind the arrow is never taxed, without needing the general notation paragraph at all. Cite 135.2.e.7.b for the notation and 813.1.d for the keyword; neither alone is the whole argument.
• THE TAX INVERTS ON AN ESCALATED SHOWDOWN THE OPPONENT OPENED, AND THIS ENTRY DID NOT SAY SO (self-correction by the walk that wrote it, 2026-09-12, within the hour). The Focus claim above is 464.2.c.1.a precisely - *"If a showdown opens as part of combat, this player gains Focus as the showdown begins"* - and the caveat is printed one line below it, 464.2.c.1.b: *"If a showdown was already ongoing when the combat opens, the player who has Focus maintains their Focus."* The board that turns it around is escalation, 323.14: *"If the current state is Showdown Open State and Combat is Staged at a Battlefield where there is a Non-Combat Showdown ongoing, that Showdown becomes a Combat Showdown."* So if the OPPONENT opened a Non-Combat Showdown first - they walked into an uncontrolled battlefield, and 345 gave Focus to them - then escalating it with your own combat leaves Focus with THEM: they close the state with an [Action] card untaxed and YOU pay the rainbow to answer, at your own Vortex. It is narrow, since it needs a Non-Combat Showdown already ongoing and opened by them, but the entry read as if attacking always buys the asymmetry. Both 464.2.c.1.a and 464.2.c.1.b were cited by nothing in this catalogue before.

Bodies no card supplies

Attack into the Vortex with your garrison

Steps

1. Have VEN-160 Mystic Vortex on the table. Its static needs no Controller - it names no player, so 190.6.d never blanks it.
2. Attack into the Vortex with your garrison. 190.3.a.1 applies Contested status, 464.2.c.1 makes you the Attacker, and 323.9 stages the Combat.
3. The Showdown opens. 345: 'As a Showdown begins, the player who applied Contested status to the Battlefield gains Focus' - that is you.
4. Play OGN-153 Overt Operation for 5 Energy and 2 Body Power. You are the card that CLOSES the state, so 358.4's first example asks only for [Action] or [Reaction], and Overt Operation has [Action].
5. 813.5.b reads whether the SPELL has Reaction. Overt Operation does not - 813.1.b's containment runs only from Reaction to Action, never back - so the Vortex charges you nothing.
6. It resolves: spend each buff you want to spend to ready that unit, then buff all friendly units. Every body of yours ends with exactly one buff, worth +1 Might each (703, 702.3).
7. Your opponent now has to answer inside a Closed State they did not close, so 358.4's second example requires [Reaction] on whatever they play - and the Vortex adds one rainbow Power to it.
8. 465.2.c reads current Might at assignment, so the +1s are already on the board when damage is assigned.
9. Do not run a [Hidden] package behind this. 811.6 gives every facedown card Reaction, the Vortex's own parenthetical says so, and you would be taxing your own free plays.
10. Three copies of Overt Operation (103.2.b), one Vortex per game (103.4.c). Nothing here loops and nothing here scores.

Per iteration

one showdown in which your trick costs its printed price and every answer to it costs one rainbow Power more, plus +1 Might on every friendly unit at the moment damage is assigned

How it ends

engine only - nothing here scores. The tax applies only during showdowns at the Vortex, and only to the player who did not close the state; three Overt Operation (103.2.b) and one Vortex per game (103.4.c)

Sources

Published elsewhere

• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 813.5, 813.5.a, 813.5.b and 813.5.c 2026-07-16
• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 358.4 and both worked examples 2026-07-16
• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 813.1.b 2026-07-16
• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 345 2026-07-16
• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt), 811.6 and 135.2.e.7.b 2026-07-16
• Card text, data/corpus_flat.txt (built from Riot's gallery content API by scripts/build-cards.mjs) 2026-09-12
• Card text, data/corpus_flat.txt (built from Riot's gallery content API by scripts/build-cards.mjs) 2026-09-12

Walked here, in this project

• Hand walk 2026-09-12 (docs/phase0/walks/2026-09-07-uncited-subrules-500-899.md), batch 18 2026-09-12 record

Walked against Core Rules 2026-07-16

Match a deck list against the whole catalogue