Quoted By:
schizo thread
oh ok let me come up with some random rrat real quick
Sanas Graduation is not coming from her it is omega going crazy with his chuuni lore shit.
If what OP said is true and AO is a common thread in the EN branch than Ina, Sana and Regis are the big players in the overarching story.
Whatever AOs influence over the world is, Sana was trying to confine it and seal it away. Ina was just the first to break the seal, slowly deminishing the guardians power (sana) and now AOs influence spreads to all kinds of people -like Regis.
>TL;DR
Sana was forced to graduate by omega for lore reasons
HoloEN Season 3 will introduce another corrupted by AO or rather a fresh face that will show weird mannerisms after their first collab with Ina.