'Renewal Resonance.'
It was the technique to rebuild one's foundation.
Something that Nux desperately needed for his wives.
His wives had an incomplete foundation, it was the biggest factor that was holding them back. It wasn't very clear back in the Forgotten Continent because people there were weak, here, however, it became much clearer.
Especially in the Ceremonial Unity Clash that took place back in the Blood Kingdom, his wives actually lost some battles.
And their opponents weren't exactly very strong either. Some of his wives even overpowered their opponent when it came to battle power and Nux knew that they had a decent chance to win.
Of course, it was partly because they didn't get the time to adjust to their new strength and were facing opponents who have been Great Sages for decades.
However, the fact was, they still lost.