Guide x Esper / Guide x Sentinel

MxF Guideverse; Female Guide for an S-Rank Male Esper who is a "Villain"

S-Rank Guide falls through a randomly spawned gate, she falls into another dimension where she is the only Guide in the entire world. The first Esper she meets is the Duke of the North, who is on the cover art to the left and the Third Prince is on the right [Meet him in chapter 17].