Discard Circling Vultures from your hand using its static ability.
Because Circling Vultures is a Lhurgoyf due to Ashes of the Fallen, Disa the Restless's first ability triggers, putting Circling Vultures from your graveyard onto the battlefield.
Activate Yahenni by sacrificing Circling Vultures.
When Circling Vultures dies, Enduring Renewal triggers, returning Circling Vultures from your graveyard to the battlefield.
Resolve the Yahenni ability.
Repeat.
This intricate loop transforms a humble bird into a relentless, self-sustaining engine. Ashes of the Fallen is the glue that makes the whole machinery tick, redefining Circling Vultures as a Lhurgoyf so that Disa the Restless can instantly cheat it back onto the battlefield whenever it hits the graveyard. From there, you discard Circling Vultures to start the chain, sacrifice it to Yahenni, Undying Partisan to feed its growing power, and let Enduring Renewal catch the bird on its way out to bounce it right back to your hand.