Urza, Lord High Artificer, Worldwalker Helm, and Urza, Prince of Kroog

Prerequisites

• Urza, Lord High Artificer on the battlefield
• Worldwalker Helm on the battlefield
• Urza, Prince of Kroog on the battlefield
• available

Steps

1. Activate Urza, Prince of Kroog by paying , creating a token copy of Worldwalker Helm that is a 1/1 Soldier and creating a Map token
2. Activate Urza, Lord High Artificer's first ability by tapping a Worldwaker Helm and a Map, adding
3. Activate a Worldwalker Helm by paying and tapping it, creating a token copy of the Worldwalker Helm token and a Map token for each Worldwalker Helm you control
4. Activate Urza, Lord High Artificer's first ability twice by tapping two Maps, adding
5. Repeat from step 3

Results

• Infinite ETB
• Infinite creature tokens
• Infinite blue mana
• Exile your library
• Cast all cards in your library without paying their mana costs
• Infinite creature copies of artifacts you control
• Infinite Map tokens