User blog comment:B214/High School DxD BorN Episode 10 Review/@comment-24421137-20150607023645/@comment-1359322-20150607025920

"Honestly the only problems I had with this is, Rossweisse not even beginning to get to Kuoh academy when the explosion happened. Teleportation is your friend Rossweisse."

But if she teleports into someone's class or somewhere which people might see, that's cause her more time than by foot, since she'll have to spend some time erasing the memories.