Himself
This information was like a second detonation through Existence.
The number of people who could see through this was too few. It had to be remembered that when the Idol Battlefield descended, many had already made their attempts at finding out what happened. It was clear and obvious to them that someone had triggered it, but they couldn't find out who that someone was.
The reason for this was that Leonel's Weapon Forces, especially their awakening process, had become a form of protection itself. They couldn't be seen through by these existences, at least not from so far away. It also didn't help that no one could have possibly guessed that the culprit was located in the Mortal Realm at the time.
Even now, the number that could put this together were far too few. The Pluto were among the very few who could; even the Void Race didn't know. Because of this, this matter would have normally remained a secret.