Crystal Moon Fragrances

It was because of Song Jia's background as Luna of the Black Moon Organization that she learned how to make perfumes.

Part of how she was coined as a genius assassin was because of her being meticulous. In order to have successful missions, she was very thorough in every detail.

She understood her target's lifestyle, personality, behaviors and habits. She knew what products they used and how they smelled like.

She could distinguish their smell among the crowd, making it easier for her to get them even with minimal visibility.

She has even used perfume to release poison several times and also made poison void of smell, taste and color.

She was a valuable member to their organization up until she asked to resign. That was around the time when she discovered that Arlo Harrell, her so-called Uncle, was actually part of the hired assassins to exterminate her family. 

In the end, she was taken too soon as well.