Feixiao before she became the General we know and love.

The events take place right after Feixiao (back then still Saran) escaped the Borisin and naturally she's not the same Lacking General we know (yet). And she also doesn't have her super speed yet.

Essentially in this scenario you in are General Yueyu who took Feixiao in and taught her everything (no details about you mentioned besides being a Xianzhou Arbiter-General).