Robot Soup is a compact combo deck built around Ob Nixilis, Captive Kingpin's triggered ability: whenever one or more opponents each lose exactly 1 life, Ob Nixilis puts a +1/+1 counter on itself and exiles the top card of your library, letting you play that card until end of turn. The deck chains this trigger repeatedly using two verified infinite loops—Dualcaster Mage plus Twinflame for infinite token copies and magecraft triggers, or Ob Nixilis plus All Will Be One plus Walking Ballista for infinite damage and library exile. Both paths win by turn 4–5 with tutors and fast mana.
Commander trigger engine: Ob Nixilis fires whenever an opponent loses exactly 1 life—not 2, not 3, just 1. This means each damage ping, each drain, each life-loss effect triggers it once. Walking Ballista's second ability (remove a +1/+1 counter to deal 1 damage) and All Will Be One (whenever you put counters on anything, deal that much damage) are the two main ways to convert Ob Nixilis's own counters into repeated life-loss triggers. The Dualcaster loop: Cast Twinflame targeting a creature you control, then hold priority and cast Dualcaster Mage for {1}{R}{R}. Dualcaster enters and copies Twinflame, targeting itself. The copy resolves, making a token copy of Dualcaster with haste. Repeat: each new Dualcaster copies Twinflame again, creating infinite tokens and infinite magecraft triggers (Coruscate Mage, Firebrand Archer, Kessig Flamebreather, and Thermo-Alchemist all ping the table for each spell cast). This loop needs only Twinflame and Dualcaster in hand plus {1}{R}{R} floating. The Ob Nixilis + All Will Be One loop: Once Ob Nixilis and All Will Be One are on the battlefield, cause an opponent to lose 1 life (via any damage source). Ob Nixilis triggers, putting a +1/+1 counter on itself and exiling a library card. All Will Be One triggers, dealing 1 damage to an opponent. Repeat: each counter triggers both abilities, exiling your library and draining the table to death. Walking Ballista plugs into this loop as the repeatable 1-damage source—remove a counter from Ballista, deal 1 damage, Ob Nixilis triggers, put a counter back on Ob Nixilis, All Will Be One drains again. Tutors and consistency: Demonic Tutor and Diabolic Intent, plus 4 more tutors find any combo piece except Ob Nixilis (the commander is always available from the command zone). Sol Ring and Dark Ritual, plus 2 more ramp pieces accelerate into these tutors by turn 2. Underworld Breach lets you cast spells from your graveyard for their escape cost (mana value plus exile three other cards from your graveyard), turning a filled graveyard into a second hand and enabling flashback spells like Faithless Looting and Strike It Rich. Protection and recovery: Reanimate, Animate Dead, and Malakir Rebirth return Ob Nixilis or combo pieces from the graveyard if they're removed. Bolt Bend and Imp's Mischief, plus 2 more similar cards redirect or copy spells to protect your combo turn or disrupt the table. Lightning Greaves gives Ob Nixilis shroud and haste, making it untargetable and immediately threatening.