Found it
An Archive of Our Own, a project of the Organization for Transformative Works
Can I have some help finding a fanfiction.On Ao3 I believe but may be fanfiction.net
SPOLIERS
It was a Star Wars I think it was a time travel or a vision based fic, padawan Obi-wan based. Xanatos was caught and put in a prison cell and Obi-Wan would visit him and bring holos. Xanatos helps him with his class work. Which if I remember helps keeps Xanatos from falling. One of Obi-wan’s teachers saw into his mind without his permission and ended up falling. She broke Xanatos out of the cell and brought him to Sideous. Later he helps Obi-wan the group that was with him(can’t remember who all it was) escape saying that she(teacher) was really crazy. There may have been Jaster and Jango at some point too.