You have at least one Aura on the battlefield attached to a creature you control.
Yenna does not have summoning sickness.
({2} magic symbol) available.
Steps
Activate Yenna by paying ({2} magic symbol) and tapping it, creating a token copy of any Aura you control attached to any creature you control, then causing you to untap Yenna and scry 2.
Ajani's Chosen triggers, creating a 2/2 Cat creature token, then attaching the Aura token to the Cat.
Activate Ashnod's Altar by sacrificing the Cat, adding ({C} magic symbol) ({C} magic symbol) .