When the tool Is unequipped, It causes massive amount of lag, why Is that?

The title says It all, when the tool Is unequip, It causes massive lag, however It stops when the beams despawn

Edit: Lag happens ONLY In testing

Script:

local Tool = script.Parent

Tool.RemoteEvent.OnServerEvent:Connect(function()
    local Anim = Tool.Parent.Humanoid:FindFirstChild("Animator"):LoadAnimation(Tool.Animation)
    Anim:Play()
    wait(2.43)
    Tool.RandomSound:Play()
    local Lazer = Instance.new("Part",game.Workspace)
    local Lazer2 = Instance.new("Part",game.Workspace)
    Lazer.Position = Tool.Parent.Torso.Position
    Lazer.Orientation = Tool.Parent.Torso.Orientation
    Lazer.Size = Vector3.new(1.716, 1.741, 0.412)
    Lazer.CanCollide = false
    Lazer.Anchored = true
    Lazer.CastShadow = false
    Lazer.Material = Enum.Material.Neon
    Lazer2.Position = Tool.Parent.Torso.Position
    Lazer2.Orientation = Tool.Parent.Torso.Orientation
    Lazer2.Size = Vector3.new(0.578, 1.741, 1.267)
    Lazer2.CanCollide = false
    Lazer2.Anchored = true
    Lazer2.CastShadow = false
    Lazer2.Material = Enum.Material.Neon
    for i=0, 50 do
        Lazer.Size = Lazer.Size + Vector3.new(0,0,2)
        Lazer.BrickColor = BrickColor.random()
        Lazer2.Size = Lazer2.Size + Vector3.new(2,0,0)
        Lazer2.BrickColor = BrickColor.random()
        Lazer.Touched:Connect(function(hit)
            local Humanoid = hit.Parent:WaitForChild("Humanoid")
            if Humanoid ~= Tool.Parent.Humanoid then
                Humanoid:TakeDamage(50)
                Humanoid.Sit = true
            end
        end)
        Lazer2.Touched:Connect(function(hit)
            local Humanoid = hit.Parent:WaitForChild("Humanoid")
            if Humanoid ~= Tool.Parent.Humanoid then
                Humanoid:TakeDamage(50)
                Humanoid.Sit = true
            end
        end)
        wait(.01)
    end
    game:GetService("Debris"):AddItem(Lazer,0)
    game:GetService("Debris"):AddItem(Lazer2,0)
end)