Or Urgash might want him to leave. Besides, something might happen to him, just like it happened to other Demon Lords (i.e., demotion).
Yes, Askh revealed her consciousness to him, but why? There was a man, and suddenly – you're in Askh's consciousness? It seems that all sources clearly indicate that Sar-Elam was the first to "establish contact" with Askh: "Sar-Elam, the first mage, touches the consciousness of the Dragon of Order and learns the nature of matter and spirit and the highest path of power" - the quote is taken from this site. I'm saying that Askh didn't just make Sar-Elam the Seventh Dragon; he fully deserved it.
Perhaps you misunderstood me; by Elemental Dragons, I mean Elrath, the Dragon of Light, Silanna, the Dragon of Earth, and so on. Further: Askh first created these Dragons, and Urgash, in turn, created the Demon Lords, the progenitors of the demon race. Of course, the Demon Lords may be weaker than the Dragons, but in terms of status, or, if you will, in terms of birthright, they are equal.
But the power of Kha-Belekh also came about thanks to Urgash. The only thing is that the Lord remained a Demon Lord, except that he became the full master of Shio.
Весьма хороший попутчик... До первого перекрестка.