Complex sentence: The Emperor eventually arrives and attacks them in Shangri-La and takes the dagger, breaks free of his terracotta form and bathes in the waters, which restores his human form and youth, replenishes his powers, and gives him the ability to shapeshift.
Split into simpler sentences: The Emperor eventually arrives and attacks them in Shangri-La, taking the dagger and shattering his terracotta form before bathing in the mystical waters. It restores his human form and youth, replenishes his powers, and gives him the ability to shapeshift.