Carth the Lion, Wrenn and Realmbreaker, Lotus Petal, and Oath of Teferi

Prerequisites

• Carth the Lion on the battlefield
• Wrenn and Realmbreaker on the battlefield
• Lotus Petal in the graveyard
• Oath of Teferi on the battlefield
• Wrenn and Realmbreaker has at least four loyalty counters on it

Steps

1. Activate Wrenn and Realmbreaker's first loyalty ability by putting two loyalty counters on it, causing a land you control to become a 3/3 Elemental in addition to its other types
2. Activate Wrenn and Realmbreaker's third loyalty ability by removing six loyalty counters from it, causing you to get an emblem
3. Cast Lotus Petal from your graveyard by paying
4. Activate Lotus Petal by tapping and sacrificing it, adding one mana of any color
5. Repeat from step 3

Results

• Infinite casts of permanent spells in your graveyard
• Infinite colored mana
• Infinite storm count