How can I make this shield expand regardless of server lag?

When the server lags, like if there are more than 50 NPCs, the circle expands slower than if there were no NPCs at all. Is there a way to make the circle expand like a real explosion, with the server lag?

This is my script, it probably isn't as efficient.

        for i = 1,50 do
            wait(0.0001)
            ex.Size = ex.Size + Vector3.new(1,1,1)
            ex.CFrame =  CFrame.new(torso.CFrame.p)
                ex.Touched:connect(function(part)
                    if part.Parent:FindFirstChild("Humanoid") then
                        part.Parent:FindFirstChild("Humanoid").Health = part.Parent:FindFirstChild("Humanoid").Health - 5
                end
            end)
        end