In a blog post, developer Arc System Works announced the next DLC character for Guilty Gear: Strive's Season Pass 1 is Jack-O'. For those who own the game's Season Pass 1, Jack-O' will be available on August 27, with everyone else being able to play as her on August 30.

Jack-O' is an artificial being created by Asuka R. Kreutz, also known as That Man, for the purpose of stopping the revival of Justice, the herald of destruction. She is a servant of his along with Raven and I-No. Aria Hale, the love interest of the series main protagonist, Sol Badguy, was used as the base for Jack-O'. This resulted in Jack-O' preventing Justice's revival in the past by fusing with Aria's soul within Justice.

Aria's soul is restored within Jack-O's, but Aria's consciousness hasn't fully manifested yet. Jack-O is now in an unstable state as her personality hasn't changed. While she tries to keep her emotions under control, she tends to be childish when she fails. In order to mitigate that, she wears a special mask to keep her composure.