Ursa's poison

"fire"

- I'll give you a vial of it in exchange for Zuko's life. Once the poison is in your hands, you do whatever you wish.



Ursa's poison is a poison Ursa made for Ozai, who used it to murder Fire Lord Azulon and take his throne, in exchange for Zuko's life.

History
Ursa's mother, Rina, was a master herbalist, and, for unknown reasons, taught her daughter how to concoct a deadly poison at some point before her departure from Hira'a.

When Ursa learned that Azulon had ordered Ozai to take Zuko's life, she struck a bargain with him: she would give him a poison that was completely untraceable to do as he wished with it, and in return, he would spare Zuko's life. Ozai agreed to the deal, but only if Ursa promises to leave the Fire Nation Capital and never return (because he feared that she would use it on him as well). After making the poison, she handed it to Ozai, and then left him without saying a word to him.

The next day, Azulon was dead and Ozai was made the new Fire Lord.

Design
The poison simply seemed as a white liquid that was completely colorless and odorless. Once ingested, the victim will simply pass on quietly, as if they had fallen asleep.