Kenrith, the Returned King + Earthcraft + Agatha of the Vile Cauldron + Repository Skaab

Kenrith, the Returned King

Earthcraft

Agatha of the Vile Cauldron

Repository Skaab

How it works

1. Activate a basic Swamp by tapping it, adding .
2. Activate Kenrith's fifth ability by paying due to Agatha, returning Repository Skaab from your graveyard to the battlefield.
3. When Repository Skaab enters, its exploit ability triggers.
4. Holding priority, activate Earthcraft by tapping Repository Skaab, untapping the basic Swamp.
5. Resolve the Repository Skaab ability, sacrificing it.
6. Repository Skaab's second ability triggers, returning an instant or sorcery from your graveyard to your hand.
7. Repeat.

This clever loop transforms Kenrith, the Returned King into a graveyard-recycling engine, made possible because Agatha of the Vile Cauldron discount-sells Kenrith's reanimation ability down to a single black mana. To fund this, you use Earthcraft to tap Repository Skaab just as it enters the battlefield, leveraging the creature to untap your basic Swamp for the necessary mana while simultaneously setting up its own exploit trigger. Once sacrificed to exploit itself, Repository Skaab's triggered ability retrieves any instant or sorcery from your graveyard, letting you loop the process indefinitely to return all your spells while generating infinite triggers.