Death Riders are one of the most revered cavalry units within the ranks of the Astra Militarum.
The Deathworld of Krieg has suffered so much destruction that it’s impossible for tanks & mechanical units to be deployed effectively amidst the ruins of the planet’s surface. In order to reinforce the front lines or to charge the enemy the Kriegsmen in the form of Death Riders are an effective unit for Kriegsmen.
Also, there is the added cool factor of having super unique minis in the form of Death Riders riding genetically engineered Terran horses charging your opponent on the table top!
Storm Gate Games 