Strength also need studying?

Slowly, Lucas opened his eyes. His black wings flapped, keeping him in the air. Suddenly, an old rough book appeared in front of out of nowhere. His eyes narrowed when he saw the title.

"Origin Heart Sword Technique"

Lucas raised his hand caught the book with his left hand. He didn't know why this book appeared in front of him. And, he doesn't care. All he knows is that he got something that could increase his strength.

Slowly, he landed on the ground and turned around his hand. The sword energy slowly rolled around his palm and formed a sword. It wasn't normal sword energy. Rather, it was a sword intent. But suddenly, he realized something.

He raised his head and looked at his sister and others, saying "Sorry!"

That sword was the path to meet Mike but he took it away from them. Although it improved his Sword Believe and condensed the Sword Intent. He was a little unhappy about himself.