My life for a fic where the reason Faceless Men change their faces regularly isn’t only to prevent them from being caught.
Imagine if they wear a certain face for too long, they start to adopt that person’s identity. They retain the ability to change faces, but they are that person. The faces hold memories already.
The real Jaqen H’ghar was a Lorathi Nobleman (I say the son of the Prince of Streets at one point who was looked like he would be elected to replace his father, and was killed to prevent it from being passed from father to son) Faceless!Jaqen wears that face while training Arya, and her training takes a lot of time so he becomes attached to that face, and Jaqen develops feelings for the little girl with a fiery spirit. Soon the identity less Faceless Man is fully Jaqen, a son of a Lorathi Prince who now serves in the Temple of Black and White. With the Faceless Man now gone, he has to leave the Temple…before they “terminate his service”