Deneb is a Silver Key Celestial Spirit known as "The Swan." He's contracted to Yukino Aguria, though their working relationship seems to involve some quirky dynamics.
During a fight with Eclipse Mother Pisces, Yukino summons him to track down the spirit who's been moving through water tunnels. Deneb's a bit prickly about his non-white wings—he preens defensively about them before anyone even comments. When Yukino tells him to do his best, he deliberately does the opposite out of sheer stubbornness. It's a weird trick that actually works: by refusing to try, he ends up genuinely trying and hits Mother Pisces hard with Summer Triangle, sending her flying. After Levy compliments him, he takes off muttering that the whole thing was annoying—though clearly he cares more than he lets on.
Content compiled by AnimeList.moe from publicly available sources.
