The next day at dawn, Mira woke up from cultivating and prepared for her sparring sessions. She had a few plans that would be beneficial for her and the disciples she'll be sparring with and one of those is to use the Training Grounds. What Mira wanted to do is have the disciples spar with her in a slow-paced battle so they understand the flaws with their swings or thoughts. A lot of times you won't notice these small things when you are moving at full speed and not paying 100% attention to every movement, but doing this will force them to pay attention and correct themselves. It can also help train their bodies as well, effectively killing two birds with one stone.
This is what Mira is all about, efficiency! Even if she will just get reincarnated if she dies, why waste time? She'd rather get the most out of every second!