His first contact with Sterl had been when the latter, under the guise of Hades, had joined the Orichalcum Kingdom's ranks.
If Sterl answered that he was from Orichalcum, everything would likely remain as it was. He might just be a powerful player, with a simple goal: to obtain that fabled Soul Treasure. However, nearly all the gods of the Orichalcum Kingdom knew that the so-called "Soul Treasure" was just an ornamental, useless trinket with no real value. It was a dead-end, a waste, which made Eterna feel a bit uneasy inside.
But, for Diana's sake, he convinced himself that it probably wasn't a major issue—he could always offer ample compensation later.
However, if Sterl claimed to be from the Ashen Temple, that would be a major problem. The aura Sterl emitted was far too powerful, and if he was indeed an undercover agent from the Ashen Temple, the consequences could be catastrophic.