"Good grief, adjacent paths?"
Tao Yu was still staying in the hospital, holding the two characteristics returned by Leonard. When he was bored, he also performed divination.
His Assassin Path's characteristic was that of the Sequence Six Pleasure Witch. It wasn't a material, but purely an extraordinary characteristic likely dropped after a Witch's death.
Through divination, he was somewhat shocked to find that the 'Arsonist' was a very good fit for him; it must be an adjacent path.
"Witches can play with black fire, and Arsonists can play with fire too; adjacent paths don't seem too strange. And the Sequence Nine of Arsonist is called Hunter, which also corresponds to Assassin. I remember Klein seemed to have one..."
Tao Yu was immune to corruption, and the extraordinaries' characteristics can be considered as the main ingredient of Magic Potions without supplementary materials.