How do you make NPC's attack enemy NPC's and not the Owner or Ally NPC's?

The NPC has a string value labeled "Owner." The value of the string value states the current owner of the NPC.

The NPC has a sword.

I want to make the sword do damage if it touches a different owner or NPC's with a different owner from its own, not its owner or NPC's with the same owner. (Make sword deal damage if it touches an enemy owner or enemy NPC, not own owner or ally NPC)

Thank you.

local Sword = script.Parent
local Handle = Sword.Handle

local Owner = Sword.Parent.Stats.Owner
local Stats = Sword.Stats
local DamageValue = Stats.Damage

local function onTouch(Part)
    local ObjTch = Part.Parent
    if game.Players:GetPlayerFromCharacter(ObjTch) then
        if (ObjTch.Name == Owner.Value) then    
            ObjTch.Humanoid.Health = ObjTch.Humanoid.Health - DamageValue.Value
            print("Damaged")
            wait(3)
        end
    end
end

Handle.Touched:connect(onTouch)

"ObjTch" means Object Touched