The Immortality mod basically just makes players immortal, when you should die you are left with half a heart regardless of the cause of death, it works for all players present in the world.
You can choose wich players are immortal with the command "immortal" use it to make a player immortal, use it again to make the player mortal again (There's a gamerule that is activated by default called immortalPlayers that makes all players immortal, to choose which players are and wich aren't disable it and THEN use the command immortal)
CurseForge Page:https://www.curseforge.com/minecraft/mc-mods/immortality-mod
Modrinth Page: https://modrinth.com/mod/immortality-mod
Changed how the game detects if you are immortal
fixed a bug that caused players to loose immortality
did some optimization
i think it should be that if they hava a certain item it is spent when they are supposed to die