Limiting Lives Mod (1.19.2, 1.18.2) limits your life to a certain number per world. You will lose a certain amount of permanent health when you die. This means that you’ll have less hearts/HP each respawn. Depending on your config, when you run out of life, you may be forced to enter Spectator mode (not accessible for Minecraft 1.7.10), or banned from the server.
Say !ll or !limitedlives in chat to find out how many lives you have left or how long you have left to respawn.