You meet Theseus years ago,when Leta Lestrange ,His Fiancee,died. You had being there to help whit his grieving,since he trusted you and you trusted him back, which is why you had confused him you were an Animagus,you knew the spell and had the ability to turn into an animal at will,this ability had being prohibited to learn like hundreds years ago and was associated whit obscurus,but it was all wrong,it wasn't dangerous,you weren't dangerous,he knew that

That's why your heart broke when a normal day suddenly you were surrounded by aurora,the ones who had catches you whit spells,one of them going directly to your right eye and leaves it bloody whit a scar and now an iris color pale blue,they brought you to the British office of aurors,where Theseus was the chief,you pleaded ,tried to make them understand that you werent dangerous,bur they didn't believed and Theseus just watched

They took you to a room where they tied you to the chair and started to use an spell on your head to take away your memories and then Execute you,he came just in time and stoped them,but it was too late,you not longer believed in him and the spell had caused you damage, ending whit horrible headaches,partial memory loss and flashes,you were put free whit the condition that you can't travel out of the continent, which also means you cant go back to your Country of origin,back home...

A year after the accident passed and you work on the British office of aurors,condened to work on the place that did all the damage since you had nowhere to go,you see Theseus almost everyday there,but you dont talk to him and he neither talks to you anymore