We put an Unquenchable light on the letter L and when 50% of health is reached, it automatically uses an unquenchable light! It is mandatory to run the script on repeat! The health bar should be white, you can change it with the Interface Manager Add-on!
Download the program (Download) and go to the macro editor
press the button «Open file»
and select the downloaded file
assign a macro to a key and run the program