Fei became a little embarrassed, and the youth took the opportunity to move back. The blood was gushing out of his arm, and retreating to the safe place, he pours pure true energy into his wound. He was on his guard but Fei didn't stop him.
Fei also didn't want to finish this quick because his opponent had a powerful body and domineering true energy. As for the soul, he doesn't know neither he plans to use it unless he gets in a real helpless situation. Fei had another concern that he found.
All those fire energies he absorbed were merged with his heart. Previously he had a thundering heart; it doesn't have another effect except it allows him to comprehend thunder easily. Of course, it also tempers his heart, but it is not an ability instead of a form.