Complex sentence: Shendu managed to reclaim all his powers, but unknown to him the uncle Chan discovered the ancient spell that turned Shendu statue, and uncle Chan suspected that Daolon Wong had knowledge of the ancient spell.
Split into simpler sentences: Shendu managed to reclaim all his powers, but unknown to him Uncle Chan discovered the ancient spell that turned Shendu into a statue. Uncle Chan suspected that Daolon Wong had knowledge of the ancient spell.