Voltaic Construct + Ashnod's Transmogrant + Incubation Druid

Voltaic Construct

Ashnod's Transmogrant

Incubation Druid

How it works

1. Cause Incubation Druid to become an artifact using Ashnod's Transmogrant.
2. Activate Incubation Druid by tapping it, adding three mana of any type a land you control can produce
3. Activate Voltaic Construct by paying 2, untapping Incubation Druid.
4. Repeat from step 2.

This clever machinery transforms Incubation Druid into a hyper-efficient mana engine by using Ashnod's Transmogrant to permanently weld the creature into an artifact in addition to its other types. Because Incubation Druid boasts an enhanced tap ability that yields three mana of any type a land you control could produce whenever it wears a +1/+1 counter, it easily pays for its own activation while leaving a handsome profit. Enter Voltaic Construct, which steps in to spend a portion of that bounty—just two mana—to untap the newly minted artifact creature, letting you cycle the loop as many times as you desire for infinite colored mana.