Complex sentence: Surrouded in black aura, Delacroix attacks Sieg once again, but Arcia steps in between Sieg and Delacroix, with her arms outstretched.
Split into simpler sentences: Surrouded in black aura, Delacroix attacks Sieg once again. However, Arcia steps in between Sieg and Delacroix, with her arms outstretched.