Although Gelford managed to keep the news under wraps for now, how long until the news blows out?
A Demon Duke's information network cannot be underestimated. In fact, Gelford believed that some of the few ancient ones were already aware of it.
Since this was the case, he couldn't afford to let this go, not when his position as a Demon Duke depended on the strength of his image.
The Blood Moon faction, his faction, would be mocked if the murder of Gelgar went unpunished. It would make him look weak and vulnerable—a target for other ambitious demons looking to make a name for themselves.
One of the Great Demon Duke Gelford's sons got killed by a mere Demon Earl. What kind of news would that make?
He can't have that now, can he? No, Gelford couldn't allow that narrative to take hold. The Demon Earl needed to be destroyed if only to preserve his own name and reputation.