This isn't a normal siege, because they didn't bring any siege weapons at all. At the forefront are those powerful entities. Seven-tier knights rise into the sky, engaging in a fierce battle with the seven-tier powerhouses opposite.
Under the overwhelming attacks, the city walls below constantly tremble.
Although the walls were reinforced using special methods, these Undead aren't very skilled at creation, and there are too few with intelligence. The reinforced walls aren't very strong and were destroyed shortly thereafter.
However, neither side continued attacking; the strongest had already clashed. The eight-tier against eight-tier battle shattered the sky into pieces. Du You's Knight Doppelganger had researched and mastered many special abilities.
