Saheeli, the Sun's Brilliance, Mana Echoes, Corridor Monitor, and Crossroads Candleguide

Prerequisites

• Saheeli, the Sun's Brilliance on the battlefield
• Mana Echoes on the battlefield
• Corridor Monitor on the battlefield
• Crossroads Candleguide on the battlefield
• Saheeli does not have summoning sickness
• available, plus an additional if you control less than three creatures that share a creature type with Corridor Monitor

Steps

1. Activate Saheeli by paying and tapping it, creating a token copy of Corridor Monitor with haste
2. When the token Corridor Monitor enters the battlefield, it and Mana Echoes trigger
3. Resolve the Corridor Monitor trigger, untapping Saheeli
4. Holding priority, if you control less than four creatures that share a creature type with Corridor Monitor, repeat steps 1 through 3 one additional time
5. Resolve all Mana Echoes triggers, adding for each creature you control that shares a creature type with Corridor Monitor for each trigger resolved this way
6. Activate Crossroads Candleguide twice by paying , adding
7. Repeat

Results

• Infinite ETB
• Infinite colored mana
• Infinite colorless mana
• Infinite creature tokens with haste