Amongst the arts he had gotten from the Hei clan, there were still two arcane arts he had yet to master. The reason was that it took a long time to master the arcane arts. Unless he was already at the Transformation stage, learning arcane art consumed a large amount of time. Amon couldn't afford to spend so much time on them considering he had many other specialties to focus on, hence he had been putting them on hold.
Despite that, he still spared a little time each day to practice one of these arts little by little. He chose to study the Flame Lance. The other arcane art, Iron Fist, was a fist offensive art. He already had Bone Shattering Shadow Fist, hence he didn't think he needed the Iron Fist art urgently.
The Flame Lance, however, was an offensive art that was capable of piercing strong defense. His Water Slicing Ring art was a very strong offensive that could seemingly cut through everything. This Flame Lance was a similar art with a piercing-style assault.
