Purple Reign

Purple Reign (パープル・レイン Pāpuru Rein) is the Stand of Katou Shimegawa featured in Part 9.

Appearance
After a traumatic event in childhood, as well as his own dislike toward Stands, Katou hides the true form of his Stand. It is only seen as a purple energy or vapour that emanates from the stand user, producing an ominous low reverberating sound when activated.

Prediction
The stand user makes three predictions, counting them on their hand by holding up their index, middle and ring fingers. The more the stand user knows about their situation, the more accurate these predictions can be.

The stand user is invulnerable during the period that these predictions are active. Each time a prediction is proven correct, the stand user closes the respective finger into their palm, starting with the ring finger and moving towards the index finger.

If a prediction is proven wrong, or inaccurately worded in some way, the purple energy fades for an extended period of time, leaving the stand user temporarily vulnerable to attack. After this period, another prediction can be made, replacing the incorrect one.

If all three predictions are proven correct, any persons or perishable objects mentioned in the final prediction will perish, and any present in the prior two predictions will be incapacitated in some way, from minor to serious damage depending on prediction.

Insta-Kill
Purple Reign can kill any person, stand user or no, almost instantaneously once the final prediction has been proven correct. The manner of killing is up to the stand user, and can take effect from any distance depending on the method.

These include:

A killing blow with a fist that is presumably Purple Reign's that emerges from the user.

An attack rush using any nearby weaponry.

Remote explosion (similar to Killer Queen)

Heart attack or any manner of instant biological death.

and many more.