Combo · ENGINE

Kill your own Undercover Agent as a cost — its Deathknell discards two Flame Chompers and the Agent reanimates itself

8 cards · chaos + fury · verified

Pieces

• Heedless Resurrection ×3 UNL-142 · engine · chaos

  [Reaction] (Play any time, even before spells and abilities resolve.) As an additional cost to play this, kill a friendly unit. Play a unit from your trash that costs no more Energy and no more Power than the killed unit, ignoring its cost.

• Undercover Agent ×2 OGN-178 · engine · chaos

  [Deathknell] — Discard 2, then draw 2. (When I die, get the effect.)

• Flame Chompers ×3 OGN-006 · payoff · fury

  When you discard me, you may pay 1 Fury Power to play me.

Payoff

Deck

• Legend domains must cover Fury and Chaos (103.1.b.1 "Cards included in your deck must abide by your Domain Identity", 103.1.b.2 "Your deck's Domain Identity is dictated by the domains of your Champion Legend"). Five legends are Fury/Chaos: OGN-251 Loose Cannon, OGS-017 Dark Child, SFD-185 Glorious Executioner, UNL-185 Bloodharbor Ripper, VEN-143 Master of Shadows.
• A board where losing the Agent for the length of one chain is acceptable. No battlefield of its own.

Prerequisites

• UNDERCOVER AGENT IS 422.4'S WORKED EXAMPLE, QUOTED: "When Discarding is part of an effect, then a player must Discard as many cards as possible from their hand. If instructed to discard more cards than they have in their hand, further discard instructions are ignored. Example: Undercover Agent has the ability '[Deathknell][>] Discard 2, then draw 2.' ... Regardless of how many cards they discard, they then draw 2." The draw is unconditional; the discard is capped by the hand, and that is the engine's real risk.
• THE DEATHKNELL FIRES, AND 808.1.d.1 CANNOT BITE. 356.2.a.1 makes the kill mandatory ("as an additional cost", no "may"). 428.1.a.1 makes a kill paid as a cost an Active Kill, and 428.1.a.1.b adds the Deathknell to the chain as a Pending Item before the kill completes. 808.1.d says the trigger is "the Permanent being Killed and sent to the Trash" - the Agent IS sent there, so 808.1.d.1, which deletes the ability when the body never reaches the trash, has nothing to remove. This is the mirror of soraka-fiora-loop-shield, which loses its Deathknell for exactly that reason.
• THE ENTRY MAKES NO CLAIM ABOUT WHICH CHAIN ITEM RESOLVES FIRST, AND IT DOES NOT NEED ONE. 428.1.a.1.b puts the Deathknell on the chain while the spell's cost is being paid and 340.1 resolves "the newest Finalized Chain Item" first; the walk could not settle from the rules text which of the two finalizes last, so it asserts neither. Both orders give the same result: the Agent is in the trash from the moment the cost is paid, so Heedless Resurrection can always find it, and the Deathknell resolves either way. If the Deathknell goes first, the two discarded cards are also in the trash when the spell looks, which only widens the choice.
• THE AGENT REANIMATES ITSELF. The filter is "costs no more Energy and no more Power than the killed unit" and the killed unit IS the Agent (E5 P1), so it always qualifies; the card never says "another unit". It returns as a new object, exhausted (143.4), at your base or a battlefield you control (355.2.a). Same shape heedless-resurrection-removal-blank found.
• THE ONE FURY POWER IS THE WHOLE PRICE OF THE FLAME CHOMPERS BODY, and this walk re-checked the reading rather than inheriting it. 051 maps card wording onto the rules' own terms and 356.1.a says "If an ability or instruction allows you to play a card 'for [Cost]', replace the card's Base Costs with [Cost]." The pool supplies the contrast: SFD-150 Last Rites also plays a unit out of the trash and prints "(You still pay its costs.)"; OGN-006 and OGN-037 Immortal Phoenix, which prints the same "pay X to play me" shape, print no such clause. Under the additive reading Chompers from the trash would cost 3 Energy PLUS 1 Fury Power - strictly worse than playing it from hand - and both cards would be dead letter against rule 002. Same reading the catalogue already uses in flame-chompers-discard-recursion and death-from-below-recurring-kill. No reading is filed.
• ARITHMETIC WITH THE DECLARED QUANTITIES. Per cast: 2 Energy + 1 Chaos Power, plus 1 Fury Power for each Flame Chompers discarded. With two in hand that is two 3 Might bodies, a hand of the same size (discard 2 / draw 2) and the Agent back on the board. THE CEILING IS THREE CHOMPERS (103.2.b) and nothing in the line returns one from the trash to hand - 422.1 defines a discard as moving a card FROM A PLAYER'S HAND into the trash - so it is one full cycle and one half, not three.
• THE KARTHUS FORK, AND THE RULE THAT SPLITS IT. OGN-236 Karthus, Eternal ("Your [Deathknell] effects trigger an additional time") would make this discard 4 and draw 4. He is ORDER. 103.1.b.1 and 103.1.b.2 forbid him in a Fury/Chaos deck and a legend has exactly two domains. The build that CAN hold him is Order/Chaos under VEN-155 Heart of the Tempest, the pool's only Order/Chaos legend and one that pays for this line by itself ("When you play a card from anywhere other than your hand, empower me", which every reanimation satisfies) - but it loses Flame Chompers (Fury), leaving VEN-094 Mask Mother and OGN-202 Jinx, Rebel as the Chaos payoffs. Two decks, not one. Same Domain Identity trap #48 hit with Chemtech Cask.
• A TOKEN IS NOT FUEL HERE EITHER. 185 "Tokens are not cards." and 186.1 (a token ceases to exist on entering any Non-Board Zone) mean a token never reaches the trash and has no printed cost, so killing one as the additional cost reanimates nothing.
• OVERLAP, DECLARED. heedless-resurrection-removal-blank already declares 3 copies of UNL-142 for the anti-removal use. Inside one deck the two are alternatives on that card, not a sum.

Steps

1. Have Undercover Agent on the board and two Flame Chompers in hand.
2. Play Heedless Resurrection for 2 Energy + 1 Chaos Power. Its mandatory additional cost (356.2.a.1) kills the Agent; 428.1.a.1 makes it an Active Kill and 428.1.a.1.b puts the Deathknell on the chain before the kill completes.
3. The Deathknell resolves: 'Discard 2, then draw 2'. 422.1.a lets you choose - send two Flame Chompers. 422.4 means a short hand discards what it has and still draws 2.
4. 422.1.b runs each Chompers trigger from the trash: 1 Fury Power each, two 3 Might bodies at your base or a battlefield you control (355.2.a), exhausted (143.4).
5. Heedless Resurrection resolves: Undercover Agent is in the trash and costs exactly its own cost, so play it back ignoring its cost. It enters exhausted.
6. Do it again with the second Heedless Resurrection - but only one Flame Chompers is left (103.2.b), so the second cycle is half a cycle.

Per iteration

two 3 Might bodies for 2 Fury Power, a hand of unchanged size, and the Agent back on the board, for 2 Energy + 1 Chaos Power

How it ends

engine only - three Flame Chompers and no route from the trash back to hand, so the discards stop being upside after one cycle and a half

Sources

Published elsewhere

• Riftbound Core Rules, Last Updated 2026-07-16 (data/Riftbound-Core-Rules-2026-07-16.txt) 2026-07-16
• Lente de descarte y recursión desde el trash — issue #95 (GitHub) 2026-09-06

Walked here, in this project

• Hand walk 2026-09-06 2026-09-06 record

Walked against Core Rules 2026-07-16

Match a deck list against the whole catalogue