Battlemage's Bracers + Heronblade Elite + Aphetto Alchemist

Battlemage's Bracers

Heronblade Elite

Aphetto Alchemist

How it works

1. Activate Heronblade Elite by tapping it, adding at least two mana of any color
2. Activate Aphetto Alchemist by tapping it, targeting Heronblade Elite.
3. Battlemage's Bracers triggers, causing you to pay 1 to copy Aphetto Alchemist's ability, targeting Aphetto Alchemist.
4. Resolve both Aphetto Alchemist abilities, untapping it and Heronblade Elite.
5. Repeat.

This ingenious loop turns a modest druid into a massive mana engine by outfitting her with Battlemage's Bracers. When Heronblade Elite taps for a flood of colored mana, Aphetto Alchemist goes to work untapping her, while the Bracers step in to duplicate the untap trigger so the Alchemist can refresh himself as well. Because the Bracers' copy ability only demands a single generic mana, the mana generated by Heronblade Elite easily covers the tax to keep the loop going indefinitely.