_G.GunDMG = 9e9 -- _G because this game is so shit it wont be detected. Switch to getgenv() if you care to.
-- also, negative dmg adds health to zombies in all modes and to plrs in survival/pvp mode
_G.KillKeybind = "E"

local gunHolding = game.Players.LocalPlayer.Character:FindFirstChildWhichIsA("Tool") or game.Players.LocalPlayer.Backpack["M4A1"]
local gunSettings = require(gunHolding.Setting["1"])
gunSettings.BaseDamage = _G.GunDMG
local InflictTarget = game.ReplicatedStorage.Remotes.InflictTarget

game:GetService("UserInputService").InputBegan:Connect(function(input,gpe)
    if input.KeyCode == Enum.KeyCode[_G.KillKeybind] and not gpe then
        for _,v in workspace:GetChildren() do
            if v:FindFirstChild("Humanoid2") and v.Humanoid2.Health >=0.0001 then
                task.spawn(function() -- why task.spawn? it does it asynchronously (it kills them all at once basically)
                    InflictTarget:InvokeServer(
                        "Gun",
                        gunHolding,
                        gunSettings,
                        v.Humanoid2,
                        v.HumanoidRootPart,
                        v.Head,
                        {},
                        250_000
                    )
                end)
            end
        end
    end
end)