747 Plan feasibility

"Do you really think you can manage something on this scale?" Sofiera asked, rough estimations of forming a fort through magic and magic alone. It would require over a hundred thousand mana. 

This was simply not something that was feasible. Sofiera, as a highmage (Tier 7) with quite excellent equipment to boost her mana regeneration, had around 6k mana and it would take her three quarters of an hour to recover after expending all her mana.

However, to avoid magic fatigue, she would prefer to spend small amounts at a time and also take breaks from time to time. Mana poison was also an issue, especially if external forces were used to boost the mana recovery. 

If she wanted to ensure her health while working, she could only use around 5k mana every hour. And she would only be able to maintain that for about a workday's hours (8).