Marvel Studios Agatha seemingly tempts Wanda into handing over her power -- cue a glorious cackle from Agatha -- in exchange for fixing Westview and letting Wanda's family live in bliss.
Prior to the debut of the final episode, speculation was running rampant that Nightmare would put in a small appearance, likely via a post-credits scene.
In truth, Wanda is secretly scattering runes around the Westview barrier - a throwback to the basement scene where Agatha used the same trick.