Because whether it is Sevyn who personally admitted it, or other Brotherhood powerhouses who have encountered it, they have all perished, leaving no evidence behind.
Furthermore, the Black Abyss Brotherhood is meticulous in its actions, making it impossible to link them to the Temple of Light through other means.
In other words, the predicament we are currently in is like suffering in silence, knowing who the mastermind is but unable to prove anything, forced to endure without being able to speak out.
At the center of everyone's focus, Leo Ray is naturally very aware of this.
Leo Ray clearly understands that in the absence of direct evidence, forcibly linking the two together would only deepen the Mercenary Guild's distrust of us, the result is self-evident.
So what needs to be done is to guide the other party to connect the two themselves, there is no other way.