Urza, Prince of Kroog, Mycosynth Lattice, Training Grounds, and Urza, Lord High Artificer

Prerequisites

• Urza, Prince of Kroog on the battlefield
• Mycosynth Lattice on the battlefield
• Training Grounds on the battlefield
• Urza, Lord High Artificer on the battlefield
• available

Steps

1. Activate Urza, Prince of Kroog by paying , creating a token copy of Training Grounds that is a 1/1 Soldier in addition to its other types
2. Activate Urza, Lord High Artificer's first ability by tapping the Training Grounds token, adding
3. Activate Urza, Prince of Kroog by paying , creating a token copy of Training Grounds that is a 1/1 Soldier in addition to its other types
4. Activate Urza, Lord High Artificer's first ability by tapping the Training Grounds token, adding
5. Activate Urza, Prince of Kroog by paying , creating a token copy of Training Grounds that is a 1/1 Soldier in addition to its other types
6. Activate Urza, Lord High Artificer's first ability by tapping the Training Grounds token, adding
7. Repeat from step 5

Results

• Infinite ETB
• Infinite tapped creature tokens