Voltaic Construct + Liquimetal Coating + Marwyn, the Nurturer

Voltaic Construct

Liquimetal Coating

Marwyn, the Nurturer

How it works

1. Cause Marwyn to become an artifact using Liquimetal Coating.
2. Activate Marwyn by tapping it, adding at least .
3. Activate Voltaic Construct by paying 2, untapping Marwyn.
4. Repeat from step 2.

This clever loop turns Marwyn, the Nurturer into an artifact creature with the help of Liquimetal Coating, opening the door for Voltaic Construct to untap her repeatedly. As long as Marwyn's power is at least 3, her tap ability yields enough green mana to comfortably pay the Construct's activation cost and loop the process indefinitely.