Brainflight

Brainflight was an alchemical substance that was addictive and dangerous.

Powers
It caused hallucinations, addiction, wildly erratic behaviour, and over time, a personality breakdown rendering the user chaotic evil. It may likely have had other effects as well.

History
The substance was likely difficult to synthesize, requiring a combination of solid alchemical and herbal skills; hedge wizards who valued money more than other people's lives traded in it, as did some other lowlives. On the other hand, while it probably contained difficult to get ingredients, it might not have been that difficult to make afterwards. It sold for about 500 gold pieces.

The substance was often limited in its availability more by legality than anything else.

Reputation
Brainflight was associated with the jaded, tense, dissatisfied, and those who were greedy.