If it was any other day, Darius would laugh to see how Aurel got humbled very quickly, but not in this situation. They were too tense to know the king's condition.
Zenith could replace him for a week or two, or even more than that, but obviously, he couldn't play the role for the rest of his life if something really happened to his brother.
More so, the death of the king would push the kingdom into utter chaos, it would jeopardize a lot of things.
But even more, Zenith wouldn't be able to leave unscathed.
People who wanted to take him down would attribute the king's death with the fact Zenith was there. It would implicate him in the long run.