variables:
    {hp::%player%} = true

on damage:
    if attacker is a player:
        if victim is a player:
            if {hp::%attacker%} is true:
                send attacker title " " with subtitle "&a%victim% &fma &a%victim's health% HP&f!"
                
command /hp [<text>]:
    trigger:
        if {hp::%player%} is false:
            set {hp::%player%} to true
            stop
        if {hp::%player%} is true:
            set {hp::%player%} to false
            stop