The snagus haim had always been strict on how much information it shared to it's members even after they had sworn their oaths.
Infimration was aonly given to it's members on a need to know bases, and so despite the fact that Kruxe had been proprtly turored on the use of darkness energy, he had been taught nothing about how seekrs used darkness energy.
Other than knowing that seekrs could always spot usrs users if darkness energy, Kruxe had no idea if there was a repercussion to seekers using it or a sort of limitation to it.
Since discovering that he was a seeker, Kruxe's mind had not once gone to use of darkness energy, but afyter eencountering Robio and fidnign himself faced with a power hat shouldn't exist in some village deep in the central continent, he began looking towards it as a replacement for his rapidly dimishign genkai.