He yelled at his torturers.  "I will get free and show you the true meaning of torture you bastards.  My ancestors were miles ahead of your amateur crap." He then uses the power in his demonic blood to cast darkness in the room, if only just to inconvenience them in the slightest bit.  His goading making them beat him harder.  He slowly regained consciousness after one session seeing a catlike halfling.  "So, I've finally snapped"