User blog comment:Тостер/Prometheus: Unusual Suspects/@comment-3221148-20161110181501/@comment-32509213-20161110211241

Could it be Carrie Cutter/Cupid? She's a former SCPD officer and definitely the type that would be obsessive enough to gather all of Oliver's old arrows and forge weapons out of them. (I don't think it's her but she does fit some of the criteria we know so far about Prometheus).