When Amano was done absorbing the memories, he came to a complete understanding, "So this was the case!! I had already reached the True God stage. It was only because I was killed once, and my memories tempered with by the system, that I forgot everything! However, once I've absorbed enough strength, I will be able to break through once more, reaching the True God realm!"
The current Amano was formed from a strand of his indestructible soul, which would not be easily extinguished. As long as a single strand still exists, there would be a chance for a revival.
However, even if there was a strand of soul left, in order to reach the peak of prowess once more, it would take a long time of accumulation of strength and energy. As long as the remnant soul of a True God has enough time, it would not be a problem to reach the half-step True God stage once more. However, the bottleneck to cross the True God realm, even for someone who had reached it before.