Holding priority, cast Naru Meha by paying its mana cost.
When Naru Meha enters, it triggers, copying Return to Action, with the copy targeting Naru Meha.
Resolve the copy of Return to Action.
Holding priority, activate Ashnod's Altar by sacrificing Naru Meha.
When Naru Meha dies, it triggers, returning it from your graveyard to the battlefield.
Repeat from step 3.
This clever loop turns Naru Meha, Master Wizard into a self-sustaining engine by utilizing Return to Action to catch her every time she hits the graveyard. When Naru Meha enters the battlefield, her triggered ability copies Return to Action, targeting Naru Meha herself so that she is primed to return whenever she dies. This allows you to immediately feed her to Ashnod's Altar for colorless mana, triggering her own death clause to bring her right back to the battlefield and repeat the entire process indefinitely.