After the explosion, Atlan's entire body, his entire Soul System, was destroyed into mere particles. He was just nothingness, floating around in the middle of nowhere.
If he was a normal human being, he wouldn't even be able to think and become conscious at this moment in time. They would be dead, plain and simple.
But Atlan was no simple being. He was the inheritor of the God of Death's legacy. He was poised to become its next ruler.
So, death had no meaning for him.
However, he felt even weaker than when he was a child. He felt like he had no such power at all.
Where am I? Atlan asked himself, but there was no answer for there was only himself in this dimension.
Where am I? He continued to ask himself, and yet, no one ever answered his question.