They often interact as teacher and student. Luna, with her vast knowledge of the old magic, can teach Twilight things that are not found in modern magic books. For example, Luna might show Twilight how to communicate with the spirits of the night.
Well, the story behind the 'Twilight Music' in 'Twilight Princess' could be tied to the game's plot and the world of twilight. Maybe it plays a role in revealing secrets or triggering certain events.
In general, the Twilight Princess manga is regarded as canon. It adheres closely to the key elements and plotlines set in the original franchise. Minor deviations might exist for artistic or narrative purposes, but the core remains consistent.
The Twilight theme could fit in through the use of supernatural elements. If the ex - boss is a vampire, for instance, it would bring in the whole Twilight - style romance with the allure of the immortal and the mortal falling in love. The idea of a dangerous yet irresistible love, like Bella and Edward's, could be mirrored in the relationship between the ex - boss and the main character.
Their relationship could develop through shared goals. For example, if there is a magical imbalance in Equestria that only their combined magic can fix. As they work towards this goal, they start to understand each other better.