Drop of Night
Like everything else about him, the Shadow Thief’s knowledge of poison was stolen. He stole the color of the night sky, and traded it back to the Moon Goddess for her knowledge of the plants and venoms that cloud the mind and cripple the body. When asked why he didn’t just steal the knowledge directly, the Shadow Thief replied, “Who says I didn’t?” and showed the bottle which contained the night sky.
The liquid inside of this tiny bottle is an inky black, though when held under moonlight, it glows faintly. When the Drop of Night is added to a poison, the poison becomes much more potent than normal. Alternatively, it can be consumed unmixed, granting the drinker the ability to see clearly in even total darkness until the next sunrise.