Ivy, Gleeful Spellthief + Jaheira, Friend of the Forest + Triton Cavalry

Cast the Aura in your hand by paying , targeting Triton Cavalry.

Triton Cavalry and Ivy trigger.

Resolve the Triton Cavalry trigger, returning the other Aura from the battlefield to your hand.

Resolve the Ivy trigger, copying the Aura spell, with the copy targeting Ivy.

Resolve the copy of the Aura spell, and the original Aura spell.

Activate the Aura token attached to Ivy by tapping it, adding .

Repeat.