Regarding the questions that you raised earlier, I will try to answer them in brief. I have already pointed out some references. Please don’t hesitate to ask questions if not clear.
1. Since energy can never be created or destroyed and is a fundamental constant in the Universe:
a. Consciousness must be a fundamental element of the Universe.
b. Kammic energy must also be a fundamental element of the Universe, but is more focused.
Consciousness can arise only from a hadaya vatthu. Since grasping another “hadaya vatthu” stops with Nibbana, that “stream of consciousness” ends with the Parinibbana (death) of an Arahant.
– Once attaining Nibbana, a living Arahant would not create more kammic energy via javana citta.
– The most difficult thing for most people to understand is “why do you want the consciousness to stop arising?” The short answer is that as long as consciousness keeps arising (in different realms, via rebirth), most of those rebirths WILL BE in the four lowest realms (apayas). Understanding that is understanding the Noble Truth of Suffering!
2. Kammic energy is only possible with the convergence of consciousness and brain, which causes mind.
NO. That I have explained. Consciousness can be there without a brain.
3. Gandhabba, a very small unit of energy, which is also subject to the Laws of the Conservation of Energy, is the wire, if you will, that allows the connection of “a” consciousness with “a” body (brain).
Gandhabba (manomaya kaya) with the hadaya vatthu IS the source of consciousness.
4. Rebirth: It is the constancy of the energies of kamma, gandhabbha, mana, etc. that keeps the wheel of rebirth in operation, barring of course an intervention of nibbana.
Is gandhabba not the link, the gap, between “a” consciousness and “a” brain. Is the seat of the mind (hadaya yatthu) not in fact triggered by the gandhabba?
Again, I have explained that now. The brain plays a role ONLY when the gandhabba is INSIDE the physical body. Data on NDE by heart surgeons provide evidence for that. Of course, numerous rebirth accounts provide evidence too.