The Martial Emperor had never concealed her "investment relationship" with Madam Harold. In fact, she could not have concealed it even if she wanted to. But what schemes she had made through that "investment relationship," what methods she had employed—she had not said, nor was there any need for her to say.
Likewise, Ronan had no need to tell the Martial Emperor what form his "investment" in Madam Harold took.
This tacit understanding between them was sufficient in most circumstances—within the framework of an alliance, it already counted as mutual respect.
And that understanding could extend into every field.
The problem was that Ronan actually knew the Martial Emperor's "investment model" inside out. At the same time, he believed that the Martial Emperor had a fairly good understanding of his own "investment model" as well.
That made things somewhat hypocritical.
Ronan was "confident" that the Martial Emperor knew his "investment model" because his "control" over Madam Harold had originally been nothing more than a deeper form of cooperation.
Madam Harold had practically invited Ronan to "move in." She needed the Demon Rune to drastically catalyze Negative Emotions, needed a more extreme environment to complete the final tempering of the Heart Burning Blade. Likewise, she needed a "new investor" to hedge against the risks brought by the previous "major shareholder"—the Martial Emperor.
As for what "risks" the Martial Emperor brought...
Within the Blood Soul Temple structure inside the Human-Faced Spiders Ronan had "herded" for the Blood Flame Order, he had seen Shepherd Marks planted by the Martial Emperor. At the time, he had not known they were the Martial Emperor's handiwork, but he had probed out the malicious intent hidden within them.
In fact, if Ronan had not intervened, the Blood Flame Order and Madam Harold would probably have become puppets