Combo · ENGINE

377.2 is what makes 'play an activated ability' mean activating one, and 377.2.a puts the rune rebate AFTER the seven Energy has already gone - so the only reliable trigger is an Empower cost nothing can shrink

4 cards · calm + mind · verified

Pieces

• Curator of the Sands ×1 VEN-145 · legend · calm/mind

  When you play a unit, gear, or activated ability with Energy cost 7 Energy or more, you may exhaust me to ready up to 2 runes.

• Steel Paws ×3 VEN-043 · engine · calm

  [Deflect] (Opponents must pay 1 Power of any domain to choose me with a spell or ability.) [Empower] 7 Energy (7 Energy: Empower me. Use only if not Empowered.) [Empowered][>] I have +7 Might.

Payoff

Deck

• Curator of the Sands (VEN-145 / VEN-192) is the legend of the line, so 103.1.b.1 is satisfied by construction; Steel Paws is mono-Calm and sits inside her Calm/Mind identity.
• Neither card is Signature (data/cards.json, signature=false on both) and neither appears in data/legality.json in either format - checked 2026-09-09.

Prerequisites

• 377.2 WAS UNCITED AND IT IS THE PARAGRAPH THAT MAKES CURATOR'S OWN SENTENCE LEGIBLE: 'Card text will refer to activating Activated Abilities with the word "use" or "play."' Her trigger reads 'When you play a unit, gear, or activated ability', and without 377.2 the phrase has no referent - an ability is not a card and is never played in the 419 sense. 827.1 then supplies the other half: 'Empower is an Activated Ability keyword', and 827.1.c.1 makes it 'functionally short for "[Cost]: Empower this. Play only if not Empowered."' Two entries already run this legend and neither cites either paragraph.
• 377.2.a IS THE COST OF IT, AND IT IS THE ENGINE-OFFSET-BY-ONE-EVENT SHAPE AGAIN: 'If "using" or "playing" an Activated Ability is part of a trigger condition, that condition is fulfilled when the Activated Ability resolves.' The seven Energy has already left the Rune Pool by the time Curator's trigger even exists, so the two runes can never help pay for the ability that produced them - they pay for the NEXT thing. This is the same wall 383.3.b puts in front of a base cost and 381 with 310.2 puts in front of an Activated payoff, reached by a third route.
• 377.2.a CUTS THE OTHER WAY TOO: THE TRIGGER NEEDS RESOLUTION, NOT FINALIZATION. 419.4.b is the same split read from the card side - 'Non-triggered abilities that check cards being played do so by means of referencing whether said cards have been Finalized' - where a countered spell still feeds [Legion] and still lowers a cost. Curator is a TRIGGERED ability watching an activation, so anything that stops the [Empower] resolving stops the rebate with it, and SFD-075 Prize of Progress, the pool's other reader of the same event, is bounded the same way.
• AND IT IS WHY THE PARTNER HAS TO BE A FLAT COST. 827.1.c.3: 'Empower abilities may also include text that alters the Empower cost. Such text is taken into account when determining a card's Empower cost for any reason.' The pool has exactly FOUR activated abilities whose Energy cost reaches 7 (swept over data/corpus_flat.txt on 2026-09-09): VEN-043 Steel Paws at a flat 7, VEN-046 Nasus, Ascended at a flat 8, and VEN-032 Frostcoat Mother and VEN-050 Grumpy Rockbear, both printed '[Empower] :rb_energy_12:. This ability costs :rb_energy_1: less for each rune you control.' 161.2.a fixes the Rune Deck at twelve and 315.3.b channels two a turn, so from the turn you control six runes those two abilities cost six or less and STOP TRIGGERING CURATOR - the board state that lets you afford them is the one that switches her off. All four are inside her Calm/Mind identity, and only the two flat ones are hers to use.
• THE ARITHMETIC. Steel Paws is E1 for a 0-Might [Deflect] body; the Empower is 7 more for a permanent +7 Might (441.2 makes Empowered 'a state for Game Objects on the board', and 441.1.b - 'An Empowered Game Object can not be Empowered' - makes it once per body). Curator readies up to 2 runes, and 164.2.a is the rune's own '[E]: [Reaction] - Add [1]', so two readied runes are two Energy back the same turn. Eight Energy for a Might 7 [Deflect] body becomes six - against VEN-046 Nasus, Ascended, who is Might 8 for E8 + 1 Calm Power plus his own Empower 8.
• THE SHORTFALL IS CURATOR'S OWN EXHAUST. 415.3.a: 'A player Readies all non-spell Game Objects they Control during the Awakening Phase on their turn.' She is readied once a turn and no oftener, so three Steel Paws are three turns and the rebate is capped at 2 runes a turn whatever the board does. Nothing in this line scores; it is a discount on a Might package, not a faucet.
• 377.2.b IS THE THIRD PARAGRAPH OF THE BLOCK AND THE CATALOGUE ALREADY USES IT - it is the rule R30 was voted on, and its worked example is Ultrasoft Poro's 'Use this ability only while I'm at a battlefield.' 377.2 and 377.2.a are its two uncited neighbours, and together the three say: 'use' and 'play' both mean activate, a condition ON activating is checked before you may activate, and a condition that WATCHES activating is met when the ability resolves.
• 204.3.a IS THE FIRST AND CLEANER SOURCE FOR THIS, AND IT CARRIES THE WORKED EXAMPLE: "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", with Riot's example being Overzealous Fan - "When I defend, you may kill me to move an attacking unit to its base" - and the note that "in order to finalize the ability to the chain, its controller must kill Overzealous Fan". 383.3.b says the same thing later in the book. The companion is 204.3.b: a cost appearing in a SPELL, in an ACTIVATED ability, or in a LATER part of a trigger's effect is paid on resolution instead, which is the 205 "pay X. If you do, Y" family and the reason the two look alike on the card and behave differently on the chain.

Steps

1. Run Curator of the Sands as your legend and Steel Paws in the Calm half of the deck.
2. Play Steel Paws for 1 Energy. It is Might 0 with [Deflect], so 809.1.c already taxes any spell aimed at it.
3. In a later Main Phase, with 7 Energy in the pool, activate its [Empower]. 827.1 makes that an Activated Ability and 377.2 makes Curator's 'play an activated ability' mean exactly this.
4. The Empower resolves and Steel Paws becomes Empowered: 441.2 makes that a permanent board state and the +7 Might is not a 'this turn' modifier.
5. 377.2.a fulfils Curator's trigger AT THAT RESOLUTION, not at activation, so the rebate arrives after the payment. Exhaust her and ready up to 2 runes.
6. Spend those two runes with 164.2.a for 2 Energy on anything else this turn; they cannot retroactively pay for the Empower that produced them.
7. At your next Awakening 415.3.a readies Curator, and a second Steel Paws can be Empowered - one a turn, three over the game at 103.2.b.

Per iteration

one Steel Paws Empowered permanently to Might 7, at a net 6 Energy after Curator's two-rune rebate

How it ends

engine - a Might 7 [Deflect] body for a net 6 Energy and no Power, once a turn, three times a game; the rebate is two runes (2 Energy through 164.2.a) and it always lands one beat after the payment it is meant to soften. Nothing here scores

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 2026-09-09, issue #187 - uncited Core Rules sub-rules 300-499 2026-09-09 record

Walked against Core Rules 2026-07-16

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