User blog comment:B214/Question and Answers 4/@comment-4547267-20141031151941/@comment-180.251.222.142-20141031193006

^Well, some of the reincarnated SG users who rebelled were disposed of by the gremory team which means issei probably killed them. If i am not mistaken the mini-dragon shot was actually made for battling in cramped area where he cannot just destroy his surrounding.