Najeela, the Blade-Blossom, and Bear Umbra

Prerequisites

• Najeela, the Blade-Blossom on the battlefield
• Bear Umbra on the battlefield
• Bear Umbra attached to Najeela
• Najeela does not have summoning sickness
• An opponent is unable to kill Najeela
• Lands you control can tap to produce at least

Steps

1. Declare Najeela as an attacker, attacking an opponent unable to block and kill it
2. Najeela and Bear Umbra triggers
3. Resolve the Najeela trigger, creating a 1/1 Warrior creature token that is tapped and attacking
4. Resolve the Bear Umbra trigger, untapping all lands you control
5. Activate all lands you control by tapping them, adding
6. Activate Najeela by paying , untapping all attacking creatures, giving them trample, lifelink and haste, and gaining an additional combat phase after this one
7. Repeat each combat phase

Results

• Infinite combat phases
• Infinite creature tokens
• Infinite ETB
• Infinite lifegain
• Infinite lifegain triggers