Here is an overview of the demo, via Koei Tecmo:
The Dynasty Warriors 9 Empires demo features the all-new evolved castle sieges, including both invasion battles and defense. Storm the enemy castle, or fight to defend your fortress in this challenging tutorial. Virtual warlords can play through each siege scenario repeatedly to discover and develop the best strategies to overpower and outthink opponents.
In addition, fans will be able to experience the game’s in-depth edit mode, enabling gamers to create their own officers before taking them into battle. The newly created characters can then be transferred from the demo version to the full game as long as you are playing the same platform on both the demo and final product.