Yes, without undergoing modification surgery or replacing the flesh and blood of his body, he could directly transform into an immortal's body.
Moreover, compared to the modification surgery Mark had originally planned, the immortal's body he obtained this way would be even more formidable.
Because not only his flesh, bones, and organ systems, but also his original Aura Core and Aura Network would undergo transformation under the influence of spirituality.
Beyond that, every power he could command within his body, as well as his mind and will, would transform alongside them under spirituality's influence.
If Mark had to describe it, it was somewhat like a Gene Modification procedure that brought earth-shaking changes to a life-form by altering its genes.
However, this Gene Modification procedure would not affect merely his physical body. His mind and power would be modified as well.
Time continued to pass in the Dream Cultivation World.
Mark continually organized the methods for stepping onto the Immortal Path, while occasionally keeping an eye on troublesome little ones like Jirachi, Mew, and Hoopa.
The task of organizing it was far less difficult than Mark had imagined.
Mark had imagined that it might take him ten days or half a month in reality—more than a decade within the Dream Cultivation World—to continuously refine everything there before he could finish organizing it.
In reality, after only a little over half a year in the Dream Cultivation World, he had already organized the method almost completely. After another three months, he could no longer find anything that needed changing.
Not only that, while organizing the method, Mark had taken the time to test the power of his mind and had luckily discovered a spiritual frequency compatible with his body.
Soon afterward, he found the spiritual frequency compatible with his will as well.