About The Great Wall: Black Powder, from BoardGameGeek:
Towers & War Machines
Employ crafty engineers to build ingenious, death-bringing machines, and to raise towers with slots for them!
Each player will be able to build towers (they are located between Wall Sections) and place chosen war machines onto them. There are three variants of War Machines: cannons, rocket batteries, and powerful siege crossbows.
Not only you will be able to use them in the game, greatly enhancing your defense potential, but also, each player will get a few upgrade cards to choose from, giving further variation and replay possibilities to the War Machines. For example, one player might favor building cannons, but they want them to be as cheap as possible, while another might concentrate on a single but very powerful one.
Additional Horde types & Siege Engines
Mongols have brought some siege engines with them! Some of the Hordes cards will come with the special engines to try and break your walls. Defend yourself against battering rams, which will break your walls, catapults, which will strike your archers, and Hordes with siege towers, which will change the way you plan your defense. They will try and counteract your towers, employing miners to tear them down.
New Hordes will add to the replayability while being able to be used in basic games as well.
New Troops!
Each Clan sends out their elite warriors to join the fray - all of the Clans will have their own unique and extremely powerful Soldier! You can upgrade one of your basic Soldier types into an elite. For example, Snake Clan will be upgrading their Archers into Chu-Ko-Nu Crossbowmen, being able to outshoot any of the opponents quickly. On the other hand, Dragon Clan, as befits their name, will equip some of their Spearmen with fire-lances. You can be sure they won't be cheap, but if you can get them recruited early in the game, you will gain a huge advantage over the Hordes (and your opponents).
New Generals, Advisor, Artefacts and Tech-Trees!
This expansion brings also new Generals, Advisors and Artifacts to further enhance replayability and allow for bigger customization of your desired tactics.
Additionally, this expansion will introduce Tech-Trees creating new exciting possibilities of development for each clan. Whit those cards you will be able to adjust your strategy and invest into Towers, War Machines or enhanced Army units!
-description from the publisher
