[[zeta (granblue fantasy)|Zeta]] in her halloween costume. Way back in 2016, there was an artwork (post #2529658) of [[zeta (granblue fantasy)|Zeta]]  and [[Vaseraga]] in halloween costumes. This concept gets re-used in their halloween version dual unit released on October 2019, along with the exact same outfits they wore in that artwork.
zeta (halloween) (granblue fantasy)