User blog comment:B214/Volume 23 discussion blog/@comment-172.56.16.164-20170415212008/@comment-31137559-20170416162016

You're acting like Issei is a one-man army. No one is invincible. Sona is very smart. She knows her servants can't take on Issei in a head-on fight. So she certainly would have created countermeasures. And plus she has only lost one match like Issei has.