Mimira seemed like a waste to Li Yao, but her escape ability was infuriating, and the sudden burst of speed was just too fast.
Even if he temporarily controlled her, once the control ended, she'd still run off. If he didn't have his flaming hawk, he could never kill this boss.
Finding her and killing her took an enormous amount of effort and a lot of time. By now, it's already dark.
System: You killed Mimira. For plot reasons, you can choose to delay the announcement. Please select whether to delay."
"Yes."
System: Please select the delay time."
"Two days."
Li Yao chose to delay for two days this time. His plan is a bit tricky, and it will take some effort. He's about to venture deep into the tiger's den again. If Mimira's death were known, who knows what would be impacted.