Xiang Kun isn't aiming to catch the mutant instantly, but rather to exhaust its sanity over time, driving it to madness with the hunger born from its Blood-drinking Period and forcing it to turn back and attack Xiang Kun.
Xiang Kun initially judged that those 'branches' scattered everywhere likely couldn't be created on a whim and required a significant amount of time to prepare. They might even be similar to the items he used to establish 'Super Sensory Contact' and 'Emotional Infusion,' needing to be 'activated' after the next blood-drinking session.
Given the mutant's actions, it seemed highly dependent on these 'branches'. Unless absolutely necessary, it would not abandon its long-established territory easily.
Moreover, knowing Xiang Kun's existence, a mutant human creature, it would probably hesitate to consume blood and hibernate freely outside, even if it could temporarily shake Xiang Kun off.
