How can I modify the script so It follows other people and damaging them Instead of you?

So What I mean Is that, I want to modify this script so when you summon a NPC It will protect you by following the other players, damaging them?

Oh and also a problem with the script Is that If being cloned lets say, replicatedstorage then, the pathfinding script stops working

script:

local NPC = script.Parent
local PathFindingService = game:GetService("PathfindingService")
local player

game.Players.PlayerAdded:Connect(function(client)
	player = client
end)

repeat wait() until player ~= nil

while wait() do
	local Path = PathFindingService:CreatePath()
	Path:ComputeAsync(NPC.Torso.Position, player.Character.PrimaryPart.Position)
	
	if Path.Status == Enum.PathStatus.Success then
		local Waypoints = Path:GetWaypoints()
		
		for i,v in pairs(Waypoints) do
			local Position = Instance.new("Part", workspace)
			Position.Position = v.Position
			Position.Anchored = true
			Position.CanCollide = false
			Position.Size = Vector3.new(1,1,1)
			
			NPC.Humanoid:MoveTo(Position.Position)
			NPC.Humanoid.MoveToFinished:Wait()
			Position:Destroy()
		end
	end
end

There is a nifty function of the Players service called GetPlayerFromCharacter() that may catch your attention.

The function in question returns a player from the given instance only if it actually finds one. If it fails to find a player associated with the instance, it returns nil.

Why is this important? Well, you can use the function as a means of failsafe:

script.Parent.Touched:Connect(function(hit)
	local plr = game:GetService("Players"):GetPlayerFromCharacter(hit.Parent)
	if plr then
		if hit.Parent:FindFirstChild("Humanoid") then
			hit.Parent.Humanoid:TakeDamage(10)
		end
	end
end)

The damaging portion of the script fails to activate if something touching it is not owned by a player.

Likewise, you can use this to create a zombie that only chases NPCs or the like by checking if the returned value is nil (not plr and plr == nil both work). In your case, you can use the function to check if the player the NPC hits is not you but rather a different player.

Also, cloning the script simply creates a new stub of code with a new PlayerAdded listener; the reason it doesn't run is because PlayerAdded does not fire more than once in solo testing. This is also the case if no player joins after you've cloned the script.