Urza, Prince of Kroog, Simulacrum Synthesizer, and Ashnod's Altar

Prerequisites

• Urza, Prince of Kroog on the battlefield
• Simulacrum Synthesizer on the battlefield
• Ashnod's Altar on the battlefield
• available

Steps

1. Activate Urza by paying , creating a copy of Simulacrum Synthesizer that is a 1/1 Construct
2. When the Simulacrum Synthesizer token enters the battlefield, its first ability and each other SImulacrum Synthesizer you control's second abilities trigger
3. Resolve the first trigger, causing you to scry 2
4. Resolve the remaining triggers, creating a 0/0 Construct artifact creature token for each trigger resolved this way
5. Activate Ashnod's Altar by sacrificing a 0/0 Construct, adding
6. Repeat step 5 for each other 0/0 Construct you control, if applicable
7. Repeat from step 1

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite colorless mana
• Infinite creature tokens
• Infinite scry 2
• Infinite creature copies of artifacts you control