Ambition.

"Even if you threatened to kill me, I would never agree with you!" Li said as he stood up from the ground shaking. He felt as though all the bones in his body had been broken and then put back together with glue. 

He knew that if Cain hadn't been holding back, his present condition would be much worse. That only seemed to make him even angrier.

"Li, it's over. Just let it go..." Sue was still bound by the golden chains Cain had used to bind her.

"Shut up! You don't know anything!" Li yelled back at Sue, causing the latter to frown.

Turning back to Cain, anger bubbled within his eyes as he maintained eye contact.

'This... He's much different from before.' Cain thought to himself.

The first impression Li had given him was that of an extremely intelligent person, who was cunning, but would never do anything to harm those he loved and wanted to protect. Now, he seemed just like a vengeful spirit.