Zirda, the Dawnwaker + Eldrazi Displacer + Drowner of Hope

Zirda, the Dawnwaker

Eldrazi Displacer

Drowner of Hope

How it works

1. Activate Eldrazi Displacer by paying C, blinking Drowner of Hope.
2. Drowner of Hope enters the battlefield, creating three 1/1 Eldrazi Scion creature tokens.
3. Activate an Eldrazi Scion by sacrificing it, adding C.
4. Repeat.

This loop relies on Zirda, the Dawnwaker to slash the activation cost of Eldrazi Displacer's blink ability down to a single colorless mana, making it cheap enough to sustain with the help of Drowner of Hope. When you pay that reduced cost to exile and return Drowner of Hope to the battlefield, its enter-the-battlefield trigger creates two Eldrazi Scion tokens. You can then sacrifice those Eldrazi Scions for the mana needed to keep the Eldrazi Displacer activating over and over, yielding an endless cascade of mana, tokens, and enter-the-battlefield triggers.