Leaving
Mira didn't need the Guardian to help her leave this place now that she was in full control. All she has to do is think about leaving and she'll be teleported back to where she entered this place.
The Guardian didn't say anything to her as he watched her turn around to teleport out of this place. He kept the same carefree smile on his face, but underneath it, all his feelings were complicated. He was happy that a successor was finally chosen, but he also knew that things would've been much easier for Mira should she not have become the Successor.
She could've cultivated freely without too many troubles except for those she caused herself or those sent by that so-called 'god' that's been messing with her. Eventually, she would've ascended into the Immortal Realm where she would go through similar experiences, just on a different scale.