Combo · ENGINE

Mask Mother off-turn — the Boon is the only Reaction discard, and 383.3.b makes her Energy a cost paid up front

2 cards · chaos · verified

Pieces

• Mask Mother ×1 VEN-094 · payoff · chaos

  When you discard me, you may pay 1 Energy to give a friendly unit +2 Might this turn.

• Lunar Boon ×1 UNL-125 · engine · chaos

  [Reaction] (Play any time, even before spells and abilities resolve.) Discard 1, then draw 2.

Payoff

Deck

• Any legend with Chaos among its two domains (103.1.b.3) — 16 names: Loose Cannon (OGN-251), Unforgiven (OGN-259), Swift Scout (OGN-263), Bounty Hunter (OGN-267), Dark Child - Starter (OGS-017), Glorious Executioner (SFD-185), Blade Dancer (SFD-195), Prodigal Explorer (SFD-199), Battle Mistress (SFD-203), Bloodharbor Ripper (UNL-185), Gloomist (UNL-193), Scorn of the Moon (UNL-197), Voidreaver (UNL-201), Master of Shadows (VEN-143), Soul's Reflection (VEN-151), Heart of the Tempest (VEN-155).
• Four runes left ready through your own turn: three for the Boon and one for the Mother's own trigger cost.

Prerequisites

• HER +2 CAN ONLY REACH THE OPPONENT'S COMBAT THROUGH THIS ONE CARD. Mask Mother's twenty-three matrix partners are play triggers, move triggers, conquer triggers, [Action] spells and activated abilities; 381 pins the last family to your own turn, and a play trigger needs you to be playing something. UNL-125 Lunar Boon is the only [Reaction] discard in the pool (swept over data/corpus_flat.txt on 2026-09-07: one row), and 813.1.c.1 lets a [Reaction] card be played 'during Closed States on any player's turn'.
• THE 1 ENERGY IS A BASE COST, NOT A PAYMENT ON RESOLUTION, AND THAT CHANGES WHEN YOU NEED IT. 383.3.b makes a cost written at the start of a Triggered Ability's effect or right after its opening 'you may' the ability's BASE COST, and 383.3.b.1 requires it to be paid 'in order to finalize the Triggered Ability to the Chain'. So you decide and pay before the trigger is even on the Chain — you cannot watch the damage assignment first and then decide. With 167 emptying every Rune Pool at the start of each player's Main Phase and 415.3.a readying your runes only in your own Awakening, that Energy has to come from a fourth rune held ready and tapped at 164.2.a's Reaction speed.
• 422.1.b is why she works at all from the trash: '"When I am discarded" abilities or other Triggered Abilities that trigger on discarding are executed after discarding has occurred', and 385.2 lets a Triggered Ability outside the Board self-describe its context. Discarding her is not a cost — it is how she is cast.
• The numbers, on a defender: 465.2.b sums the defending Might and 465.2.c assigns that much damage, so +2 Might is +2 damage assigned in the opponent's combat, and 465.2.c.3 forces lethal onto one unit before the next, which is where two extra points of assignment decide whether a second body dies. The card economy of the Boon is +1 (discard 1, draw 2) and you choose the card that goes.
• This is the off-turn half of mask-mother-scrapyard-champion, which is the on-turn half: the Champion discards TWO Mothers in one instruction for +4 Might and draws two back, but only in your own Main Phase. Same payoff card, different window, different arithmetic. jinx-rebel-lunar-boon-reaction stacks on the very same discard if Jinx is also on the board — one Boon, three triggers.
• 'Give a friendly unit +2 Might this turn' is a plain continuous modifier, not a 702 buff counter, so 702.3's one-per-unit cap never applies and two Mothers discarded in one turn stack on one body; and nothing that spends a buff (OGN-146 Wallop, SFD-101 Fae Dragon) can be fed from it.
• 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. Keep a Mask Mother in hand and four runes ready when you pass the turn.
2. On the opponent's turn, in the Closed State their spell or their combat opens, tap three runes (164.2.a) and play Lunar Boon (813.1.c.1).
3. Discard Mask Mother to the Boon, then draw 2.
4. Her trigger fires from the trash (422.1.b, 385.2). Tap the fourth rune and pay the 1 Energy to finalize it (383.3.b.1).
5. Give a friendly unit +2 Might this turn — on a defender, 465.2.b and 465.2.c turn that into two more points of assigned damage.

Per iteration

+1 card, +2 Might on one friendly unit this turn, for 4 Energy

How it ends

engine — +2 Might on a defending body and one net card, inside the opponent's turn, for 4 Energy paid off runes held ready; 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 2026-09-07, issue #169 — matrix families rows 6-18, second pass 2026-09-07 record

Walked against Core Rules 2026-07-16

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