Just like what he said, Kiba failed to activate the ability like the rest. He can only produce a black light on his arm, which also extinguishes faster. Fein listed what he has to do. Kiba just needs to practice how to maintain the black light and make it thicker.
How does he exactly do that? Well, it was for him to figure out. Fein doesn't want to spoonfeed them. And he had complete trust in their talent, so he didn't have to worry about it either.
Just like that, days passed. The peeping gaze still appeared occasionally. There's even a time he was bathing, and it appeared. Fein speculates that Jackson would attack once he was far away from the Ranger's Eye Base. He still didn't know why Jackson wants to attack now. He's worried that Jackson might have already ascended like him. Well, he could still kill him though, even if he was an S rank.