Rith, the Awakener + Breath of Fury + Phyrexian Altar + Urabrask the Hidden
Rith, the Awakener
Breath of Fury
Phyrexian Altar
Urabrask the Hidden
Infinite colored manaInfinite combat damageInfinite combat phasesInfinite death triggersInfinite creature ETBInfinite creature LTBInfinite mana creatures you control can produceInfinite creature sacrifice triggersInfinite untap of creatures you controlInfinite creature tokens with haste
How it works
Deal combat damage using Rith and the creature with Breath of Fury attached, triggering Rith and Breath of Fury.
Resolve the Rith trigger, causing you to pay 2 to create at least four 1/1 Saproling creature tokens.
Resolve the Breath of Fury trigger, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to a Saproling token, then causing you to untap all creatures you control and to get an additional combat phase after this one.
Move to your next combat phase, and deal combat damage using Rith and the creature with Breath of Fury attached, triggering Rith and Breath of Fury.
Holding priority, activate Phyrexian Altar three times by sacrificing three Saprolings, adding 2.
Repeat from step 2.
This elegant loop turns Rith, the Awakener's color-dependent token generation into an unstoppable engine by leveraging Breath of Fury to chain endless extra combat phases. Phyrexian Altar provides the crucial mana-producing sacrifice outlet to fuel Rith's hefty {2}{G} payment time and time again, while simultaneously turning extra Saproling fodder into resources. Finally, Urabrask the Hidden ensures that every newly created Saproling token immediately enters the fray with haste, ready to attack and perpetuate the cycle without missing a beat.