The Afro Droid is a robot that was financed and constructed by the Empty Seven.
Normally, the Afro Droid looks just like Afro, but after Afro destroyed his hull, his more robot-like "skeleton" became visible along with new abilities such as a big laser cannon
The Afro Droid was a big part of the Empty Seven's plan to kill Afro and get the Number 2 headband.
Using the data that Otsuru was able to collect from Afro's Dreams, the Empty Seven were able to adapt the fighting style of Afro for their Droid and improve it to ensure Afro Droid's victory. But Afro was able to win by remembering the teachings of Sword Master and thus becoming more unpredictable. After destroying the robots hull, Afro fought the Droid's skeleton that was very different in terms of fighting style, but the Afro Samurai was still able to outsmart him.