Siege

Lucy didn't kill any humans at this point to avoid being detected by various Arcane Spells that could sense bloodlust.

She continued with the original body's daily job.

She worked at a quaint bookstore, a repository of knowledge and stories that humans treasured. It was a perfect place for her to learn about humans.

With each customer that entered, she practiced the art of human interaction, her smile a well-crafted facade, her words were like a melody of mundane pleasantries.

'Mhmm… I'm getting better and better at this… Infiltrating that castle shouldn't be that difficult once I'm confident enough…' Lucy mused as she considered testing herself by slaying a few nobles or even Arcanists who held high positions in various Organizations.

Once she killed them without being noticed, that would be the time to aim for the Shadow Immortal in his castle.

For now, she had to continue adapting to the Human Realm…