It was as if Gabriel didn't really care about giving the test of the Crown, not caring about his Talent at all. He wasn't entirely wrong either.
Even if Gabriel went through the test of the Crown, his talent couldn't be affected since it was given to him by the Grimoire. No Numen could ever compare to a Grimoire that came into existence because of a proper god and not because of Demigods.
A Numen couldn't affect the Grimoires like that. Similarly, they couldn't mess with the talent and Soul Strength that was provided by the Grimoire.
Let alone controlling his soul for him to tell the truth, the Numens couldn't even touch his soul that was already protected by the Grimoire.