I tried to track down the ending for that story a while back. 'The Abandoned Luna's Journey to Power' is a webnovel I started reading on a few different apps, and honestly, the conclusion felt a bit scattered depending on where you read it. The core ending, from what I pieced together, has Luna fully mastering her inherited celestial magic and refusing to take back her old mate, the Alpha King who discarded her. Instead, she establishes her own pack on the borders of the realm, becoming a power in her own right that he's forced to negotiate with as an equal.
There's a final confrontation where he begs for forgiveness, offering her the Luna title back, and she basically tells him his territory is too small for her ambitions now. She ends up with the royal scholar character, Aris, who supported her from the beginning. It's a very 'rejected mate becomes sovereign' finish. Some versions have an extra epilogue where she brokers a peace treaty between the shifter clans and the fae, using her unique position as a bridge. The writing in the last act got pretty rushed, though, with a magical council subplot that was introduced and resolved in like three chapters.
I remember feeling the final battle was anticlimactic—she wins more through a political maneuver than an actual fight, which fits her character arc but left me wanting a bit more spectacle. The very last scene is just her looking at her new territory from a tower, satisfied and alone but not lonely. It's a quiet ending for a story that started with so much drama.