Banba agrees to work for Saruhiko labs.  He's invited to their lowest level, where the cause of all the incidents is revealed. Then it gets loose...
Pitch Black
Rabenschwarz
Episodio 12 
 Negro Azabache
Episodio 12 
 Negro Azabache
NOIR DE JAIS
Episodio 12
Nero 
come la notte
Preto-azeviche