Teshar triggers, returning Scrap Trawler from your graveyard to the battlefield.
Activate Lotus Petal by tapping and sacrificing it.
Activate Umbral Collar Zealot by sacrificing Scrap Trawler.
When Scrap Trawler dies, it triggers, returning Lotus Petal from your graveyard to your hand.
Resolve the Umbral Collar Zealot ability.
Repeat.
This elegant loop transforms the humble mana-acceleration of Lotus Petal into a self-sustaining engine by leveraging the recursive power of Teshar, Ancestor's Apostle. Whenever you recast your artifacts, Teshar triggers to pull Scrap Trawler back from the graveyard, while Scrap Trawler itself ensures that the sacrificed Lotus Petal bounces right back to your hand upon death. Meanwhile, Umbral Collar Zealot serves as the reliable sacrifice outlet that fuels the graveyard-bound loop and lets you sculpt your draws along the way.