It is a fern-like Stand that manifests after DIO's awakening. However, due to Holy's gentle nature, the Stand goes out of control and begins debilitating its user.
Holy's Stand initially takes on the form of a fern-like plant covered in thorns, reminiscent of her father Joseph Joestar's Stand Hermit Purple, first manifesting at the center of her back. However, as time passes, the Stand gradually spreads across her body, as if it was consuming her, growing from every part of her until it completely covers her.
The design of Holy's Stand was likely inspired by raspberries, which are considered an invasive species in some parts of the world, spreading uncontrollably and disrupting the local ecosystem due to their vigorous growth.
Color Schemes
The series is known for alternating colors between media, the information presented below may or may not be canon.
Although most Stands are used for fighting, Holy's Stand works against her. Due to her gentle, non-violent nature, she lacks the mental strength necessary to control the Stand, slowly making her ill with a harmful high fever and nearly ending her life by the end of Part 3.[1]
Holy's Stand works against its user, barely moves, and has no known abilities or powers other than giving Holy the ability to see other Stands. Holy's Stand also can't harm others, passing through other Stand users who try to touch it. However, Holy's Stand wasn't fully formed yet, and she simply lacked the fighting spirit to control it properly, hence its self-destructive capabilities. It is unknown how it would have turned out if she could properly manifest and control it.
The anime team gave this Stand the name "Fern-like Stand" (シダのようなスタンド, Shida no yō na Sutando) in production artwork, likely due to its plant-like appearance.[2]