Thanatos Echo

At 35% health the player enters a panic state. Vision narrows and the field of view shifts, so the player can lose their bearings. Sounds become unreliable: a growing heartbeat, frightening noises, and footsteps behind the player that whisper the player's own name. Natural regeneration is disabled in this state, and fear stops wounds from being healed by eating.

Below 15% health the agony state begins. Under Agony, the character's movements stop answering as they normally would: sitting down on the ground while holding Shift grants an edge for building and jumping, yet the view shakes hard and breaking blocks becomes impossible until the player recovers. There is also a 15% chance each time that the item in hand is dropped.

Death carries over. The player respawns with maximum health intact, but each death removes one heart from the maximum, and lower health makes a later panic state come sooner. The mod is a Forge mod for 1.21.1 – 1.21.11 and runs on client and server, so the server and every player need it. It is released under the MIT License and is open source, and it is compatible with OptiFine.