Excava, the Risen Past + Solemnity + Breath of Fury + Concordant Crossroads

Prerequisites

• Breath of Fury attached to another creature you control with mana value 3 or less.
• You either control another nontoken creature with mana value 3 or less, or have a creature card with mana value 3 or less in your graveyard.
• An opponent cannot block creatures you control.

Steps

1. 1Declare Excava and the creature with Breath of Fury attached as attackers.
2. 2Excava triggers, returning up to one creature with mana value 3 or less from your graveyard to the battlefield. It won't enter with a finality counter on it due to Solemnity.
3. 3Deal combat damage using the creature that has Breath of Fury attached.
4. 4Breath of Fury triggers, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to another creature with mana value 3 or less, then causing you to untap all creatures you control and to get an additional combat phase after this one.
5. 5Repeat each combat phase.

Effects

• Infinite combat damage
• Infinite combat phases
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control