Suppose that across Gensokyo, your favourite 2hu have been hit with a Stand arrow and manifested a Stand on their own. What, do you guy think, each one's Stand is, and what's it ability?
Ex:
Name: Kogasa Tatara
Stand: Umbrella Surprise
Ability: Surprise people.
Description: A stand in a shape of an ordinary-looking Karakasa. Due to it ability, it held many gimmicks and function, hidden within itself to surprise anyone seeing it. Upon being surprise, a "Surprise" energy immediately manifested from the target, and being sucked into the Stand itself to power itself and it users, leaving the target emotionally drained in propotional to how much they're surprised. However, it's indiscriminate to everyone, even it own user, as long as they're surprise by it own action, so the user itself could be drained, and even knocked unconcious if they aren't vigilance...
The more it gained energy and store within itself, the more it can surprise, and the more it could drain it target to surprise again. It could consistently gain power infinitely as long as it could still surprise people, and they haven't being drained yet. A surprisingly powerful Stand if done right.