Nightwish

Nightwish is a narcotic or drug that is mostly used in battle because it can restore at least 20% of a person's aura.

However, because of it's very sweet taste, many have sold and bought the drug. The project to produce more of these have been shut down.

However, criminal organizations create their own and decides to sell more of the Nightwish.

Positive
As stated, it allows the user to have at least 20% of his/her aura restored.

Negative
Abuse of the drugs, such as taking more than 3, will eventually make the user, not only addicted to it, but will also cause hallucinations that will drive the drug user mad.