First of all, please pay attention to Grammar when posting. This question is a good one, but the topic title was not formulated right. I just changed it to: “Mind Creates Matter, What creates the Mind?”.
y not said: “So this means that the individuality (of every singular ‘mind’ ) persists after the attainment of Nibbana”
After attaining Nibbana, there is no “individuality” left in this world of 31 realms, i.e., there is no rebirth. Please read the subsection on “Nibbana“.
The “lifestream” of an individual ceases to exist in this world of 31 realms: “What Reincarnates? – Concept of a Lifestream“.
Also read: “Nibbāna “Exists”, but Not in This World“.
This question keeps coming up in different forms. Please make sure to understand what is meant by Nibbana. If not clear, let us get it resolved here.