There was a reason why Vask was the one who survived. It was a decision made by the remaining Monarchs; devoting all of their [Chaos Energy] to saving him. In fact there was a choice between him and another Monarch but then, Pilliade entered into the argument.
"This is not even a question. Among us, Vask is the youngest, most talented and, the only one with a kind of power that could continually develop and be enhanced."
"So you're saying we should rely on the kid for such an important mission?"
"I believe our fight is enough of a statement to prove his worth correct?"
Even as the world of Gaia was ending, Vask was still the twelfth seat among the Monarchs. But this was only because he had no time to climb up the ranks anymore.