User blog comment:B214/Volume 21 info & spoilers/@comment-83.7.233.159-20160420144354/@comment-27876048-20160423222717

While I do agree with your statement overall, I'll have to disagree when it comes to Rossweisse in regards to her techniques and proficiency with magic I agree with you but Rossweisse has plenty of power, Issei has literally referred to her as a "magical cannon".