1. I think this is a good opportunity to go through the process step-by-step. I will start with a lifestream X. That lifestream was in a Deva realm (thus we can call it Deva X), expired the life there, and just grasped a human existence (human bhava).
2. When that Deva X disappeared from the Brahma realm, a human gandhabba (same lifestream X) appeared in the human realm. It is a “manomaya kaya” with a hadaya vatthu and five pasada rupa. Suppose this human bhava has kammic energy to last 1000 years.
3. That human gandhabba was drawn to a womb after 10 years and thus born with a human body. Let us call that human X1. Then X1 lived with that human body for 100 years and died. During that life, he killed someone and thus gained kammic energy to support existence in a niraya (hell).
4. When X1’s physical body died, the gandhabba came out. After 10 more years, it was again drawn into a womb, and now there is human X2. This human X2 cultivated anariya jhana during this life and died after 100 years.
5. Now, X’s lifestream still has many years of kammic energy left for the human bhava. However, cultivating an anariya jhana is an anatariya kamma. It brings vipaka immediately when that physical body X2 dies.
6.Therefore, the human bhava ends, and X grasps a Brahma bhava. That means the set of hadaya vatthu/5 pasada rupa disappears and a NEW SET of hadaya vatthu/2 pasada rupa corresponding to the Brahma Bhava appears in that Brahma realm. This is Brahma X now.
7. Note that the kammic energy to get a niraya existence (while as human X1) still associated with that lifestream. However, it was not an anantariya kamma. This kammic energy still can bring a niraya existence in the future.
I will stop here for now. Let us discuss any questions up to this point.