Urza, Prince of Kroog + Metalworker + Retreat to Coralhelm + Ancient Den
Urza, Prince of Kroog
Metalworker
Retreat to Coralhelm
Ancient Den
Infinite colorless manaInfinite copies of artifacts you controlInfinite creature tokensInfinite creature ETBInfinite landfall triggersInfinite creature copies of artifacts you control
How it works
Activate Metalworker by tapping it and revealing at least three artifact cards from your hand, adding at least six C.
Activate Urza by paying 6, creating a token copy of Ancient Den that is a 1/1 Soldier.
When the Ancient Den token enters the battlefield, Retreat to Coralhelm triggers, untapping Metalworker.
Repeat.
If you have four or more artifact cards in hand, this combo nets infinite colorless mana, and you may target any artifact you control to get infinite copies of them.
This ingenious loop turns Urza, Prince of Kroog into a master smith by leveraging the massive mana-producing engine of Metalworker. By using Metalworker's tapped ability to generate the six colorless mana needed for Urza's copy activation, you can constantly churn out token copies of Ancient Den. Each time an Ancient Den token enters the battlefield, Retreat to Coralhelm's landfall ability triggers to untap Metalworker, resetting the whole cycle so you can generate infinite colorless mana and infinitely replicate any artifact you control.