David summoned Shadow Servant as he flew forward, placing one hand on Shadow Servant's shoulder and the other on Black Dragon Alexis perched upon his shoulder.
The Soul Energy of fifteen Level 5 Zerg flowed from Shadow Servant's body, through David's body, and into Black Dragon Alexis's soul, healing His severely damaged soul.
"Alexis, while we have this chance, I'll do my best to collect more Soul Energy. Once the Interstellar Federation fleet opens fire, there won't be any Soul Energy to harvest!" David said to Black Dragon Alexis with a smile.
His conversations with Black Dragon Alexis were conducted through the Master-Servant Contract. Even the individual reconnaissance equipment beside him could not intercept any information.
"Lord Arthur, you must also be careful. At your current level, Blade Domain has a duration limit!" Black Dragon Alexis reminded him while absorbing Soul Energy.
"Blade Domain has a duration limit?" David asked strangely.
That had truly been his first time using Blade Domain. He had not felt that activating it consumed much, and by his estimation, with his energy reserves, maintaining Blade Domain for ten days would not be a problem.
"Your battle just now involved only a dozen or so targets, so the consumption was naturally minimal. In addition to mental and physical exertion, Blade Domain also consumes the Power of Rules. You merely forcibly learned the Blade Rule. Before your strength reaches the peak of the Legendary rank, you cannot fully control the Blade Rule. As a result, the Power of Rules from your Blade Rule cannot recover in time!" Black Dragon Alexis explained.
David calmed down. After testing the sheer power of Blade Domain, he really had become somewhat impulsive.
If Blade Domain could last for ten days, he was confident he could hold off the Zerg attack alone.