Rings of Brighthearth + Aphetto Alchemist + Gilded Lotus

Rings of Brighthearth

Aphetto Alchemist

Gilded Lotus

How it works

1. Activate Gilded Lotus by tapping it, adding three mana of any color.
2. Activate Aphetto Alchemist by tapping it.
3. Rings of Brighthearth triggers, allowing you to pay 2 to copy Aphetto Alchemist's ability and choose a new target for the copy.
4. Resolve both copies of Aphetto Alchemist's ability, untapping Aphetto Alchemist and Gilded Lotus.
5. Repeat.
6. Once you have infinite mana, you may untap any artifact or creature instead of Gilded Lotus in step 4.