The only problem was that the Dark King needed the shadowLaw, which Sterl did not possess. Naturally, he couldn't take the time to slowly comprehend the shadowLaw. Instead, Sterl had forcefully acquired the Core of Shadow through a massive influx of funds. This item had numerous demons in Hell that possessed related attributes, and the amount Sterl had originally extracted was not enough to give birth to even a single seed of Law after refining.
Thanks to the acquisitions facilitated by the Sosia and Sonis sisters in the Hall of Valor, he barely managed to gather enough resources and even consumed a bit of blood force to directly unlock shadowLaw. The shadowLaw provided Sterl with four significant enhancements.