Holding priority, cast Naru Meha by paying its mana cost.
When Naru Meha enters, it triggers, copying Graceful Reprieve, with the copy targeting Naru Meha.
Resolve the copy of Graceful Reprieve.
Holding priority, activate Umbral Collar Zealot by sacrificing Naru Meha.
When Naru Meha dies, Graceful Reprieve triggers, returning Naru Meha from your graveyard to the battlefield.
Repeat from step 3.
Resolve all Umbral Collar Zealot abilities from step 5.
This clever loop centers around Naru Meha, Master Wizard, whose entry triggers the copying of an instant or sorcery spell. By using Graceful Reprieve to establish a deferred return effect on Naru Meha, you create a safety net for when you sacrifice the Wizard to Umbral Collar Zealot's ability. Because Umbral Collar Zealot allows you to sacrifice creatures at instant speed to surveil your deck, you can bin Naru Meha to trigger the delayed revival from Graceful Reprieve, instantly bringing Naru Meha back to copy the spell all over again.