CarlManvers2019
Writers Blocked Douchebag
What does he do with it after pricking himself with said arrow and getting a STAND POWER
jojo.fandom.com
He realises it can be used to give other people STAND POWER as well
Presume this is after he becomes a signatory of the Unseelie Accords
Bow and Arrow
The Bow and Arrow (弓と矢, Yumi to Ya) (more specifically the Arrow (矢, Ya)) is a powerful item introduced early in Diamond is Unbreakable. In Part 4, it becomes a major plot-driving force for its role as the source of many new Stand users; and it is revealed that its influence extends back to...
jojo.fandom.com
He realises it can be used to give other people STAND POWER as well
Presume this is after he becomes a signatory of the Unseelie Accords