Silvanus's Invoker + Simic Growth Chamber + Agatha of the Vile Cauldron

Silvanus's Invoker

Simic Growth Chamber

Agatha of the Vile Cauldron

How it works

1. Activate Simic Growth Chamber by tapping it, adding two mana.
2. Activate Silvanus's Invoker by paying 1, untapping Simic Growth Chamber and causing it to become an 8/8 Elemental with trample and haste in addition to its other types until end of turn.
3. Repeat any number of times.
4. Once you have infinite mana, you may tap and untap any other land(s) you control, and if you control lands that can produce and , use the mana to activate Agatha of the Vile Cauldron's ability.

This brilliant loop relies on Agatha of the Vile Cauldron to slash the activation cost of Silvanus's Invoker down to just a single generic mana. With that discount in place, Simic Growth Chamber can tap for two mana, use one to untap itself via the Invoker's newly cheapened ability, and leave you with a net profit of one mana each cycle. Once you have generated infinite mana of any color your lands can produce, Agatha of the Vile Cauldron's second ability can be repeatedly activated to give your entire board infinite power, toughness, trample, and haste.