Lurking Roper + Cryptolith Rite + Judge of Currents + Xenograft

Lurking Roper

Cryptolith Rite

Judge of Currents

Xenograft

How it works

1. Activate Lurking Roper by tapping it, adding one mana of any color.
2. Judge of Currents triggers, causing you to gain 1 life.
3. Lurking Roper triggers, untapping itself.
4. Repeat.

This clever loop transforms a simple life-gain trigger into a limitless engine. By using Xenograft to grant the Merfolk type to all your creatures, Judge of Currents is primed to watch every move they make. When you tap Lurking Roper for mana using Cryptolith Rite, Judge of Currents rewards that tap by granting you a life. That stray point of life immediately satisfies Lurking Roper's untap condition, resetting the creature so you can tap it again for endless colored mana.