Use one of Seiko's drugs to humiliate her

Ruruka knew that if Seiko trusted one thing in this world, it was the drugs she created.

It was kind of creepy.

Ruruka waited until Seiko had to take a bathroom break from her research before she could sneak in to find what she wanted.

She looked at the shelves filled with the drugs that Seiko had worked hard on.

Just from a glance, Ruruka could see some that would be instantly useful in her revenge but which one would she pick?