Karn, Legacy Reforged + Karn, Silver Golem + Lithoform Engine + Voltaic Construct

Prerequisites

• Lithoform Engine does not have summoning sickness.
• You control at least one additional artifact.

Steps

1. 1At the beginning of your upkeep, Karn, Legacy Reforged triggers.
2. 2Holding priority, activate Karn, Silver Golem by paying , causing Lithoform Engine to become an artifact creature until end of turn.
3. 3Activate Lithoform Engine's first ability by paying and tapping it, copying Karn, Legacy Reforged's ability.
4. 4Resolve the copy of Karn, Legacy Reforged's ability, adding for each artifact you control that cannot be spent to cast nonartifact spells.
5. 5Activate Voltaic Construct by paying , untapping Lithoform Engine.
6. 6Repeat from step 3.

Effects

• Infinite colorless mana that can't be spent to cast nonartifact spells
• Infinite untap of artifact creatures you control