The doomwheel is Clan Skryre engineering at its most honest: a colossal wheel driven by rats sprinting on an internal treadmill, crackling with warp lightning generators, and steered — in the loosest possible sense — by a warlock engineer strapped within. Once rolling, it goes where momentum, terrain, and the panic of the treadmill rats decide.
In battle a doomwheel is a rolling catastrophe, spitting arcs of green lightning while grinding over infantry, cavalry, and any clanrats too slow to scatter. Skryre sales doctrine holds that everything a doomwheel crushes was, by definition, in its way, and that an engineer who cannot accept a little friendly attrition has no business operating wonder-weapons.