Strange runes
Under the lead of Heinz, the Soul Forging existences of the Magi invader force proceeded to continue with the construction of new magic towers less than three days after they finished the last one.
There was some resistance at the beginning when the Cultivator notified the Rank 4 Magi since the rest of the army was not ready to act so soon, and the moment they entered in a battle against their counterparts in the Heavenly race, they couldn't focus on anything else.
Although those at Rank 3 and beneath would not be useful in a battle of their level, they could still protect the tower to a certain extent from the attacks of a Rank 4 life form with the help of the force field.