Toaru Kagaku no Railgun - Insist on the need of outsiders (Doujinshi)Bugaisha no, Sono Hitsuyousei o Shuchou suru; 部外者の、その必要性を主張する

This is the book of an "WHAT-IF" during NT9 in one of those "Phases". Enjoy https://www.melonbooks.co.jp/fromagee/detail/detail.php?product_id=455756