This loop turns Kenrith, the Returned King into a relentless necromancer by leaning on Agatha of the Vile Cauldron, whose passive ability drastically discounts creature activated abilities based on her power. With that cost reduction in place, Kenrith’s graveyard-reanimation ability costs just a single black mana, which is easily funded by tapping a basic land through Earthcraft. By using Earthcraft to tap Sakura-Tribe Elder the moment she re-enters the battlefield, you can sacrifice her to fetch another basic land and fuel the engine all over again. This creates an endless cycle of sacrifices and graveyard returns that ultimately strips every single basic land straight out of your library and onto the battlefield.