Lotus Ring + Puresteel Paladin + Nemata, Grove Guardian + Concordant Crossroads

Lotus Ring

Puresteel Paladin

Nemata, Grove Guardian

Concordant Crossroads

How it works

1. Activate Nemata's first ability by paying 2, creating a 1/1 Saproling creature token.
2. Activate Lotus Ring's equip ability by paying 0 due to Puresteel Paladin, attaching it to the Saproling.
3. Activate the Saproling by tapping and sacrificing it, adding .
4. Repeat.

This clever loop relies on Nemata, Grove Guardian to continuously spawn 1/1 green Saproling creature tokens, enabled instantly by Concordant Crossroads giving those tokens haste so they don't suffer from summoning sickness. Once the tokens hit the battlefield, Puresteel Paladin makes the equip cost of Lotus Ring completely free thanks to its metalcraft ability, allowing you to instantly strap the heavy artifact onto the fresh Saproling. From there, you tap and sacrifice the equipped token right back to Nemata, cashing in the creature to generate three green mana from Lotus Ring's activated ability—more than enough to pay the {2}{G} needed to start the whole cycle over again.