He obtained the necessary weapons through trading with the continent, led his army from Kyushu to Honshu, built a fortress at Mt. Oe and attacked Heian-kyo with catapults, but in reality he was just being used as a pawn by the behind-the-scenes manipulator, Seimei ABE.
大陸との交易で武器をそろえてひそかに九州から遠征、大江山に砦を築き投石器で平安京を攻撃したが実際は黒幕の安倍晴明に使い捨ての駒として利用されていた。