Brick from the Great Wall of China

Origin
The Great Wall of China is a stone, brick and wooden wall in northern China built by various Chinese dynasties to defend against Mongol attackers and various warlike tribes. Construction began in the 7th century BC, but most of what remains today is from the Ming Dynasty (1368 - 1644). Some estimates put the number of workers who lost their lives during construction from thousands to a million.

Effects
When dropped between two opposing forces, it recreates a large stone wall. To do so, it takes the lives of anyone nearby, except the users and their opponents. The size and strength of the wall is directly dependent on the age and health of the lives taken.