Complex sentence: In the Reckoning Dispater's legendary tower was the first to be attacked and was laid seige to by Zariel however Mammon managed to help Dispater beat the seiging army back and then they both poured into Maladomini, to attack Baalzebul.
Split into simpler sentences: In the Reckoning Dispater's legendary tower was the first to be attacked and was laid seige to by Zariel. However, Mammon managed to help Dispater beat the seiging army back and then they both poured into Maladomini to attack Baalzebul.