Isilia

is Shiro's best friend.

Second Life
After sacrificed herself for Shiro, she woke up in the elven continent 5 years before the Great Metamorphosis.

During that time, she realised that her level had been reset and so did her class. Trying to work her way back to her peak, she was able to become a level 200 powerhouse by the end of the 5 years.

But before she could complete her class up, the metamorphosis occurred, sending the entire elven continent to earth.

It was also during this time that started to travel around the world in search of information as this was something beyond her understanding.

Several worlds combining together into one with Earth.

She had initially hoped that Aria would be included and that she could find Shiro but even after 15 years of searching, she hadn't found anything that could suggest that Aria had merged as well.

But despite the lack of result, she had the information to create several theories of which she decided to return to the elven continent to continue her research.

Third Life
She interacted with Shiro by disguising herself a the Librarian of the Hidden Sect Arwen.

After she passed away for a second time, she woke up in her old body which was heavily damaged. It was barely healed and she was on the verge of death. She didn't know how many years had passed but things looked different and Li Jian was around the area at the time. He saved her and brought her back to the sect where she was healed and as repayment, she decided to help him out with some of his tasks and look after the library. She also continued her study on different worlds, dungeons and things related to the system. During this, she managed to make a breakthrough and became the Elven Queen of Aria. Usually, this would be impossible since she's technically 'not a part of Aria' anymore but thanks to her research she managed to achieve it.