Because he created a perfect clone copy of himself, Atlan was able to create a clone that had all of his powers in its own Soul System.
The reason why he hadn't been doing this all this time was because he didn't think it was possible. However, when the White Beauty puppet died, he found that it wasn't possible to revive her by creating another puppet in her likeness.
So, he was forced to think about other sources of inspiration for his new puppet. However, he didn't have any other figure that he could come up with. After all, he needed to be intimately familiar with the subject he was trying to make into a puppet.
With no other choice left, Atlan was forced to draw from himself. After all, he knew himself the best, so he thought that it would be easy to create a clone of himself.
When he created the clone, he instinctively knew that this was what he should have been doing in the first place.