A way to control the protos energy
It was only recently that Azzy made a breakthrough to the legendary realm, and to hide his real soul realm, he had to suppress it through the Decarune seal instead of focusing on stabilizing his realm.
And then, his young age is to blame for his eruption. If he had been living for centuries or millennia, he would be mature enough to ignore such insults.
Of course, it isn't that Azzy is vulnerable to insults. But, due to the fact that he never ended up in such a position, it made him lose control for a moment.
The result?
Previously, when he lost such control, almost the entire city was affected. The same result occurred but the nearest surrounding area suffered the most.