Рандомно вывести одну из форм через определенное время

Type[] forms = new Type[10];
 
forms[0] = typeof(Form1);
forms[1] = typeof(Form2);
forms[2] = typeof(Form3);
forms[3] = typeof(Form4);
forms[4] = typeof(Form5);
forms[5] = typeof(Form6);
forms[6] = typeof(Form7);
forms[7] = typeof(Form8);
forms[8] = typeof(Form9);
forms[9] = typeof(Form10);
 
Form frm = (Form)forms[new Random().Next(10)].InvokeMember(null, System.Reflection.BindingFlags.CreateInstance | System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public, null, null, null);
 
// показать форму через Show() или ShowDialog()
frm.ShowDialog();

        void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            var rnd = new Random();
            FormList[rnd.Next(FormList.Count)].Show();
            bw.RunWorkerAsync();
        }

private List<Form> FormList = new List<Form>();

private List<Type> FormList = new List<Type>();

            FormList.Add(new Form1());
            FormList.Add(new Form2());
            FormList.Add(new Form3());
            FormList.Add(new Form4());

            FormList.Add(typeof(Form1));
            FormList.Add(typeof(Form2));
            FormList.Add(typeof(Form3));
            FormList.Add(typeof(Form4));

FormList[rnd.Next(FormList.Count)].Show();

((Form)FormList[new Random().Next(FormList.Count)].InvokeMember(null, System.Reflection.BindingFlags.CreateInstance | System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public, null, null, null)).Show();

        void bw_DoWork(object sender, DoWorkEventArgs e)
        {
            // Тут ставим время скока ждать (вместо 5000 ставим свое)
            Thread.Sleep(5000);
        }

       
 void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
            var rnd = new Random();
            FormList[rnd.Next(FormList.Count)].Show();
            bw.RunWorkerAsync();
        }