Although I set the data to 0.0, the drone will still be killed by NPCs

I just tested and it worked fine for me. If you are doing this via a permission profile, you have to reload the plugin for it to apply to existing drones. Exception is if you attach something to the drone, in which case the settings should refresh at that time. If you are seeing this issue with specifically Drone Turrets, please be aware that there is a separate section of the config (and separate permissions) for the toughness settings of those drones.

WhiteThunder

I just tested and it worked fine for me. If you are doing this via a permission profile, you have to reload the plugin for it to apply to existing drones. Exception is if you attach something to the drone, in which case the settings should refresh at that time. If you are seeing this issue with specifically Drone Turrets, please be aware that there is a separate section of the config (and separate permissions) for the toughness settings of those drones.

The drone is equipped with a turret NPC to attack the automatic turret, and the drone will also lose blood