Description:

Use the Ten Blocks Behind item (interact/use) to summon a completelyinvisible shadow that materializes 10 blocks behind you and slowly creeps toward you at about one block per second; touching it kills you instantly. Manual uses are unlimited — every use spawns another shadow and multiple shadows can chase you at once — and looking directly at a shadow causes it to glitch and despawn after one second. The mod also guarantees one automatic shadow spawn per player at a random time each in-game day while you are online; in Creative you can remove them with a command like /kill @e[tag=shadow_entity] if needed.