What is the Jade Prison?
The Jade Prison is where the Dragon-Blooded imprisoned the essences of slain Solars after the Usurpation, in order to prevent them from reincarnating. The Jade Prison was recently destroyed by the Deathlords, releasing half of the Solar essences back into Creation. The remaining half were divided between the Yozis (who took 50) and the Deathlords (who used the remaining ~100 to create Abyssal Exalted).