Saheeli, Radiant Creator + Lightning Runner + Aethertide Whale + Exalted Sunborn

Saheeli, Radiant Creator

Lightning Runner

Aethertide Whale

Exalted Sunborn

How it works

1. At the beginning of your combat phase, Saheeli triggers, causing you to pay EEE to create two token copies of Aethertide Whale with haste.
2. When the Aethertide Whale tokens enter the battlefield, they trigger, causing you to get twelve E.
3. Declare Lightning Runner as an attacker, triggering its ability, causing you to get EE and then pay eight E to untap all creatures you control and to get an additional combat phase after this one.
4. Repeat each combat phase.

This explosive energy-fueled loop turns the combat step into an endless parade of destruction, anchored by Saheeli, Radiant Creator to double your token output and Exalted Sunborn to double those tokens yet again. When Aethertide Whale enters the battlefield, its massive influx of energy fuels Saheeli's combat trigger, which is doubled by Exalted Sunborn to spit out multiple whale copies at once. With your army fresh and ready, Lightning Runner steps in to attack, generating and spending energy to untap your entire board and grant you an infinite succession of additional combat phases.