This mighty armed (hero) is certainly a portion of Hari's (Krishna) energy. The lord (Krishna) wishes to take back to himself his that energy.
एष ह्यस्य महाबाहुस्तेजोऽशश्च हरेधुंवम्। तमेव पुनरादातुमिच्छत्युत तथा विभुः॥