Combo · ENGINE

444.2.c - a [Reaction] Add may be activated at the instant you are told to Pay, so a trigger's base cost needs nothing banked

4 cards · fury · verified

Pieces

• Shakedown ×3 OGN-033 · enabler · fury

  [Reaction] (Play any time, even before spells and abilities resolve.) Choose an enemy unit. Deal 6 to it unless its controller has you draw 2.

• Immortal Phoenix ×1 OGN-037 · payoff · fury

  [Assault 2] (+2 Might while I'm an attacker.) When you kill a unit with a spell, you may pay 1 Energy + 1 Fury Power to play me from your trash.

Payoff

Deck

• Both cards are mono-Fury, so 103.1.b.1 is satisfied by any legend carrying Fury. The census run against data/cards.json on 2026-09-12 gives sixteen names; among them Hand of Noxus (OGN-253), Glorious Executioner (SFD-185), Pridestalker (UNL-183), Piltover Enforcer (UNL-187) and Butcher of the Sands (VEN-141).
• Neither card is Signature (data/cards.json, signature=false on both) and neither appears in data/legality.json in either format - checked 2026-09-12.

Prerequisites

• 444.2.c WAS UNCITED AND IT LIFTS A CONSTRAINT THIS CATALOGUE HAS BEEN PRICING FOR MONTHS. The rule, verbatim: 'Players may activate abilities that Add resources with the Reaction keyword at any time that they are instructed to Pay resources. Those abilities finalize and resolve immediately, ignoring normal restrictions.' Nothing in data/combos.json or data/synergies.json cited 444.1, 444.2, 444.2.a, 444.2.b, 444.2.c, 444.3 or 444.3.a before this entry.
• AND EVERY RUNE IN THE GAME IS SUCH AN ABILITY. 164.2: 'A Basic Rune always has the following two Abilities:' - 164.2.a '[E]: [Reaction] — Add [1].' and 164.2.b 'Recycle this: [Reaction] — Add [C].' Both carry the keyword, so 444.2.c reaches them. The standing model in this project is that a cost due at FINALIZATION must be banked beforehand, because 312.2.c says 'When the turn is in a Closed State, all pending chain items finish being finalized, and they control the next item on the Chain' - nobody receives priority in between. That is true of PRIORITY and it is not true of paying: 444.2.c is a permission that does not need priority at all, and it says so - 'ignoring normal restrictions'.
• WHY IT MATTERS HERE AND NOT ON YOUR OWN TURN. 167: 'Every player's Rune Pool empties at the start of each player's Main Phase and the end of each player's turn.' So on the opponent's turn you begin with an EMPTY pool twice over, and anything you must pay there has to be found on the spot. On your own turn you could simply tap before acting; on theirs you cannot, and 444.2.c is the only paragraph that lets you.
• THE COST IS A BASE COST, WHICH IS WHY THE WINDOW IS THE PROBLEM. 204.3.a: 'When Costs within Instructions appear as the first part of the effect in triggered abilities, the cost is taken to be the base cost of the triggered ability. It must be paid to finalize the triggered ability.' 383.3.b.1 says the same from the other end. So the Phoenix's 1 Energy + 1 Fury Power is due while the trigger is still Pending, inside the Closed State 312.2.c describes. 429.2 and 429.2.a then make the rune's Add resolve at once and out of order: 'Priority and Focus will not pass from Add abilities being finalized or resolving, and will resolve before any other outstanding items on the chain are finalized.'
• THE KILL ATTRIBUTION IS WHAT MAKES A BURN SPELL SATISFY 'KILL A UNIT WITH A SPELL'. 428.5.c: 'When one or more Units is killed due to a Cleanup, that kill action is attributed to the spell or ability that resolved immediately prior to that Cleanup that dealt damage to the Unit or Units.' 428.5.c.1: 'The player responsible for the deal action is responsible for the kill action.' Shakedown performs no kill instruction - 143.2.a kills in the Cleanup - so without 428.5.c the Phoenix would never fire. 428.5.c.2 is the boundary: 'If the Cleanup that caused the units to be killed was the Combat Cleanup, the sources of the Combat Damage are attributed the kill action', so this never works off combat damage, only off the spell.
• AND 'YOU KILL' IS THE SAME RESPONSIBILITY TEST AS 411.4. 411.5.a: 'Spells and abilities have attribution for game actions, while players have responsibility.' 428.5.c.1 hands you the responsibility for the kill because you were responsible for the deal, which is the clause the Phoenix's 'When you kill a unit with a spell' actually reads.
• WHAT YOU BUY, PRICED WITH BOTH CURRENCIES. On the opponent's turn: 2 Energy + 1 Fury Power for Shakedown (813.1.c.1 admits a [Reaction] card in any Closed State on any player's turn), then 1 Energy + 1 Fury Power found at the instant of finalization for the Phoenix. Four resource-units total and a 3 Might body from the trash, repeatable across turns because 415.3.a refills the runes at your Awakening. Three Shakedowns are three cycles.
• THE OPPONENT CHOOSES WHICH HALF THEY GIVE YOU, AND THAT IS THE ENTRY'S SHORTFALL. Shakedown reads 'Deal 6 to it unless its controller has you draw 2' - they will hand you the two cards whenever the body is worth more than that, so the Phoenix half is not on demand. What the line guarantees is that WHEN the kill half happens, the recursion is never priced out of reach, which was the open question.
• THE PHOENIX ARRIVES IN TIME TO BLOCK. 355.2.a puts a played unit at 'the controller's Base or a Battlefield the controller controls', and 464.2.c.3.a gives a body that becomes present after the designation moment its own designation 'during the Cleanup phase following the action that caused it to become present.' Neither 464.2.c.3 nor 465.2.b filters by exhaustion, so 143.4 costs him nothing on defence - but [Assault 2] is 807.1.c, attacker-only, so he defends at his printed 3.
• NO POINT IS SCORED. This is removal plus a body, on the opponent's turn, and nothing in it Conquers or Holds; the class is ENGINE for that reason and not for want of arithmetic.

Steps

1. Get Immortal Phoenix into your trash - discarded, killed, or milled; 385.1 and 385.2 let a card's own trigger describe its context from outside the board.
2. On the opponent's turn, inside any Closed State their own spell or trigger opens, play Shakedown as a [Reaction] (813.1.c.1) for 2 Energy + 1 Fury Power, tapping runes normally with priority.
3. Shakedown resolves and deals 6. If the opponent takes the damage rather than giving you two cards, 143.2.a kills the body in the following Cleanup.
4. 428.5.c attributes that kill to Shakedown and 428.5.c.1 makes you responsible for it, so the Phoenix's trigger goes on the Chain as a Pending Item.
5. 312.2.c hands out no priority while it is pending - and it does not have to. 444.2.c: activate a rune's [Reaction] Add right there, 'at any time that they are instructed to Pay resources', and 429.2.a resolves it immediately and ahead of everything else on the chain.
6. Pay the 1 Energy + 1 Fury Power, finalize the trigger (204.3.a), and play the Phoenix from your trash to a battlefield you control.
7. 464.2.c.3.a hands him the Defender designation in the next Cleanup if a combat is open there, and 415.3.a readies your runes at your own Awakening so the next Shakedown is fully funded.

Per iteration

an enemy body dead on the opponent's turn and a 3 Might unit back from your trash, with nothing pre-banked

How it ends

engine - one 3 Might body recurred from the trash per Shakedown that connects, for 2 Energy + 1 Fury Power on the spell and 1 Energy + 1 Fury Power found at the instant of finalization; three copies of the spell is three cycles, and the opponent decides each time whether to hand you the kill or two cards

Sources

Published elsewhere

• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt) 2026-07-16

Walked here, in this project

• Hand walk 2026-09-12, issue #187 - uncited Core Rules sub-rules 300-499 2026-09-12 record

Walked against Core Rules 2026-07-16

Match a deck list against the whole catalogue