These are the forms that you will unlock after you and Issei train in the Room of Spirit and Time.
Mastered Ultra Instinct 2 (I can't find any picture of Mastered Ultra Instinct 2. So just imagine Mastered Ultra Instinct 2 is just like Mastered Ultra Instinct but with bluish-white bioelectricity cackling around your body.)
Super Saiyan Purple
Super Saiyan Purple 2
Super Saiyan Purple 3
Super Saiyan Purple 4
Your Ultimate form,
Super Saiyan Rainbow
Super Saiyan Rainbow 2 (just imagine there are bioelectricity crackling around on your body)
Super Saiyan Rainbow 3
Super Saiyan Rainbow 4