Two parts of a whole
Layton was aware of Lilith's surprise but the situation in front of him wasn't too bizarre as the mastermind behind its cultivation Layton was able to easily follow the traces and understand why it understood the law, it was nothing more because the current body was a world master as opposed to its original apprentice stage of cultivation, with his increase in cultivation it naturally awakened its talent which 'discharge' a fairly common talent belonging to the lightning branch of laws, this coupled with the enormous amount of bioelectricity it emitted naturally during the process of Layton cultivating it into a clone that its talent was repeatedly exercised, in addition to the special circumstance of the awakening of will it naturally grasped some fragments of the lightning law.