Lister had pondered why Aurola made that choice at the time.
Rather, during the time right after he left, he was thinking every moment... besides those superficial reasons, why exactly did Aurola choose to expel him?
Later, he felt he had gradually found the answer.
Did Aurola need Lister?
If you asked anyone who knew the two of them to evaluate, they would definitely give an affirmative answer.
During the more than ten years Aurola was in power, with Lister's assistance, she saved Saint Viliana from being a huge corpse emitting the stench of death to a giant in the early stages of recovery from a major illness. And anyone could see that once this giant stood up, it would be a world-shaking event.
But Lister himself came to the opposite conclusion... at least at that time, Aurola indeed no longer needed him.