Steward of the Harvest, Sword of the Paruns, and Serra's Sanctum

Prerequisites

• Steward of the Harvest on the battlefield
• Sword of the Paruns on the battlefield
• Serra's Sanctum in exile

Steps

1. Activate the creature with Sword of the Paruns attached using Serra's Sanctum's ability by tapping it, adding at least Activate Sword of the Paruns by paying , untapping the creature
2. Repeat

Results

• Infinite untap of creatures you control
• Infinite mana creatures you control can produce
• Infinite white mana