Intellect syringe

An intellect syringe was a fearsome enchanted medical tool that was said to have come to Toril from another plane or demiplane sometime before the mid–14 century DR.

Description
This medical device was exotic to those unfamiliar with this technology and looked intimidating due to its tough needle. For those who'd seen such tools in the past, the intellect syringe appeared as nothing more than a regular but sturdy metal and glass syringe.

Powers
Use of the intellect syringe required a gruesome and cruel ritual to be completed. The target was to be restrained, conscious, and helpless. The syringe was then injected up into the victim's brain through the base of their skull. Next, the item began to slowly draw the victim's cerebrospinal fluids out. This process was slow, excruciatingly painful, and resulted in death after 10 minutes of torture. The next step was similarly stabbing the needle into the recipient's brain. Once the Syringe was empty, it granted the recipient improved intelligence, stolen from the now-dead victim. This boost of intelligence lasted for a month. After one month, the gained intelligence slowly reduced over the course of several weeks back to the recipient's original mental capacity.

But use of the intellect syringe had its dangers for the recipient. Upon injection, there was a chance that the recipient suffered from a deterioration in mental reasoning. In some rare cases, this could lead to a fit of murderous insanity. This effect could be removed via a heal or a wish spell, while spells like remove disease and remove curse had no effect.

History
The intellect syringe was taken from a villainous necromancer by Harper agents. The item was deemed dangerous and was hidden away in one of the many secret Harper vaults. Being a bardic organization, they were unwilling to destroy knowledge, even such vile and evil knowledge. Harpers elected to hide the wondrous items away and keep them under lock and key.