Urza, Lord High Artificer, Urza, Prince of Kroog, and Threefold Thunderhulk

Prerequisites

• Urza, Lord High Artificer on the battlefield
• Urza, Prince of Kroog on the battlefield
• Threefold Thunderhulk on the battlefield
• undefined available

Steps

1. Activate Urza, Prince of Kroog by paying , creating a token copy of Threefold Thunderhulk that is a 3/3 Soldier in addition to its other types
2. When Threefold Thunderhulk enters the battlefield with three +1/+1 counters on it, it triggers, creating six 1/1 Gnome artifact creature tokens
3. Activate Urza, Lord High Artificer's first ability six times by tapping six of the tokens, adding six
4. Repeat

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