Fearing the possibility that Demon Lord Kirgil would use his remaining power to cause as much destruction as he possibly could to the Dwarven Kingdom, Flunra wasted no time and propelled himself after him.
In the entire Dwarven Kingdom, plus the reinforcements, he was the only capable one.
He was the only one capable of fending Demon Lord Kirgil.
Even though there were a couple of strong Dwarves that were tasked with defending the Dwarven Kingdom, as well as Lady Lauren and Daniel who were informed by Adhara of a possible attack, they would at best be able to stall a moment against Demon Lord Kirgil.
Demon Lord Kirgil is too strong for them.
Looking through the lens of power hierarchy, he's in the upper ninth-rank realm.