Abyss
"You know what they are?" Reign asked curiously as he stabbed his sword through the prince's chest before using his powers to stop his soul from leaving.
Reign couldn't capture the Prince's soul, but he could very much trap it and not allow it to get away.
As for Aethion's words, Reign felt the solemness in his voice. It was clear that Aethion was worried about whatever it was that he had found out.
With the soul of the prince being forced to stay in its dead body, Reign and Aethion could finally talk.
"What are they?" Reign asked as Aethion sighed deeply
"Inhabitants of the Abyss"
"The Abyss, isn't that the power that Tank had gained during his evolution?" Reign asked in confusion as Aethion nodded at him.
"Yes, Tank had managed to gain the power of the abyss back then, but that was merely a small wisp that had combined with his skill in order to form a new, more powerful one," Aethion said before sighing again.