This question has actually been on my mind, as more and more people seek to access Christ's resurrection body.
Some thoughts I carry, First of all, I don't associate the physical body that died on the cross with Zarathustra/Master Jesus. Remember, the Solomon Jesus died aged 12 and Master Jesus's higher members passed over into the Nathan Jesus, who suddenly was speaking so convincingly in the temple, whereas previously this being had seemed a bit "backward" (but loving!). So my understanding (correct me if I am wrong) is that the physical body which was taken all the way through the crucifixion is the body of the Nathan Jesus, the body prepared in the Nathan line of heredity. The body of a soul which had never before incarnated in a physical body. Thus I also associated this body with the original idea of the human body, the cosmic image of the human body, aka Adam Kadmon. This body was prepared through heredity to be as perfect a physical body for the indwelling of a god as possible in those times.
The Solomon Jesus had a body which was prepared so as to allow the fullest development of the wise Zarathustra soul, to the height of its potential, so that a worthy sacrifice could be made for Christ. The body of the Zarathustra individuality died at age 12. The higher bodies of Zarathustra (at least ego, astral, and also including etheric) could then work through the physical and etheric bodies of the Nathan Jesus to both purify them (in the sense that initiation purifies the impact of earthly incarnation) and refine them with the highest achievements of human development so far.
Now, remain aware that the Nirmanakaya of Buddha was working in the Nathan Jesus as well!
The Zarathustra soul worked in the Nathan embodiment from 13yr-30yr. Thus the period of development and wanderings belong to Master Jesus, to the Zarathustra ego. Master Jesus had full knowledge of the full life of Jesus (both streams) to age 30, and this was shared with the existing sheaths of the Nathan Jesus.
Then, the Ego of Zarathustra offered itself up at the Baptism in the Jordan, forsaking its connection with embodiment. At this time, the Being of Christ could enter into the prepared embodiment and transform human incarnation from inside. This process did involve a penetration through the entire structure of sheaths, and a burning up of the body also. The physical body became fully transformed at the end of the 3 years, just as the Mystery of Golgotha took place. The physical body was transformed down into the very substance (ash) of the bones, etc.
Then, and let us not forget, the descent into hell, into the sheaths of the earth body took place, by Christ. In this descent the very elemental nature of matter was transformed into a transformed elemental quality which is typically called by the term "phantom body" or "resurrection body." This body is not physical in the sense of mineral ash that we are used to on the physical plane, but it is a complete body structure of a transformed substance that provides a kind of supra-mineral skeleton for Spirit Man. Such a body can live and work in various spheres, including spiritual ones.
All bodies are manifestations of consciousness, yet consciousness at different levels can be called, for example, astral, or etheric, or physical... Astral bodies carry structures of consciousness which include various forms created by the soul forces of thinking, feeling, and willing, for example. Etheric bodies carry dynamic flows of form and force, of life, of livingness in time, of development. Physical bodies become individualized and exactly formed in space (within time) as specific bodies at specific locations in specific periods of time. The densification and individualization is deeper.
Christ transformed the dense and individualized physical body of the Nathan Jesus into a new archetype for a densified form of manifestation of consciousness that can be utilized by all of humanity in its process of ascending back into spirit in individualized form (into Spirit Man). This deed includes a transformation of the physical body into a resurrection body. The resurrection body has quite different forces acting within it than the original (descending to incarnation) blueprint of humankind.
A spiritual scientific exploration of the substance and forces of the resurrection body would indeed be a very valuable contribution to spiritual research!
I am tempted to offer a scheme that has become important to me regarding the various sheaths of Christ, particularly now, as multiple beings assist with this. I will seek to refrain. But for me, the question has always been, what to call this transformed Physical Phantom of Christ? I do connect it with the Nathan being, who was held back, and who entered physical incarnation with a sublime innocence and with extraordinarily pure etheric forces. But what to call this physical body? The term "Nathan Soul" is used quite a bit, but this refers to the soul as it was transformed through Christ's incarnation, not to the body per se. "The resurrection body" is probably the most accurate term.
OK I can't help but give my current schema thoughts regarding the sheaths of Christ at this time, as Christ works actively in the etheric world.
Christ Himself as Universal Ego of Humanity & Spirit of Earth Development.
I of Christ
Michael as the "countenance" or "personality" of Christ, in conjunction with the imprint of the Zarathustra Ego, in-between the I and Astral Body, helping mediate these, helping mediate the connection of the Christ I to the Spirit Self of earth-sun humanity.
Astral Body of Christ
Vidar as the carrier/sustainer of the etheric body of the Etheric Christ, and closely bound with Nirmanakaya of Buddha, mediating the connection between Christ's Life Spirit and Spirit Self
Etheric Body of Christ
Nathan Being (at intersection of physical and etheric), mediating the relationship of the pure etheric forces (Life-Spirit) of Christ with the pure template of the physical body - the resurrection body (Spirit-Man).
Resurrection Body
Well, to explain this properly would take hours or pages, and I realize this not the right place.
However, I would welcome further thoughts on these matters. This is living spiritual research for me, and I do believe that we benefit from sharing with each other our hypotheses and understandings and experiences.
Offered humbly,
Susan O