Dark
This kind of makes me think of Metal Sonic in a lot of ways. Mostly because it is a failure that ultimately becomes a badass boss requiring twelve characters to finally stop it which is a lot I think. Metal Overload had a first part that sounded like this except a lot more dramatic though.
The sounds I am hearing here kind of give off a feeling of desperation as you and the foe stand face to face. One is simply a clone created from the other one's memories. They jump back and the fight begins..
The tune is twisty.
Overall, dark and twisty.