The Legend of Ben 10: Book 1, Sentience.

Chapter 3: The Nursery (Part 2)

Ben had only been to five star restaurants a few times in his life. 

Each time had been an event held by the Plumbers for him and his grandfather in honor of the large amount of work they put in to keeping the Universe at peace. 

However this time, it was because the scary homicidal sister of his friend's friend, who according to them, was a master manipulator and certified psychopath, was now taking him out to eat to find out if he knew where her brother whom she wished to kill was, which he actually KNEW but couldn't tell her. 

Hurray. Talk about backfiring plans. 

the scary part was that Ben had NO idea WHY he himself had been brought alone. Azula didn't know did she? Was she interested in the Omnitrix?! 

He had no experience regarding this highly dangerous person that Sokka, Toph and Katara often talked about with caution and fear. 

He knew that once, she had pursued Team Avatar so relentlessly that the entire party nearly went crazy from lack of sleep, which made Ben wonder if Azula herself ever slept.   She had even resumed tormenting and manipulating Zuko  when he had been apparently accepted back into the Fire Nation by his father. 

Ben had met psychopaths. He knew a few criminals that still scared him through their sheer memory. But if half of what he heard about Azula were true, he wasn't even sure that Vilgax could intimidate her or force her under his thumb. 

There were several people who Azula fell into the same category as on his friend's descriptions alone, and they were Zs' Skayr, Aggregor, Michael Morningstar and Zombozo. People who couldn't be bought or paid off and whose minds and inability to feel remorse made them far more dangerous than even their powers implied. And that was considering that some of them were already dangerous on their powers alone. 

Considering all his victories over the years against these enemies, Ben sometimes wondered if he just had some sort of extreme luck. Especially considering that alien weapons, like guns, for all intents and purposes, should have counter measures against alien powers right? Shouldn't an alien rifle be designed to punch through something like Cannonbolt's armor?  Perhaps there were just so many alien species with different abilities, it was just too expensive or too much work to design anything like that.  That would definitely make sense at least. 

After all, not every alien had super powers. But here he was getting off topic when he was sitting at a five star restaurant having lunch with a PSYCHOPATH!!

"Now." said Azula as she and Ben sat at the booth in the large restaurant filled with sweeping architecture, most notably the paintings of Dragons and Phoenixes dancing through clouds and mountain villages. "I must admit you are a strange one, simply put, you've ignited my curiosity Bob Fire."

"Have I now?" Ben asked. 

"You are adopted that is apparent. I am used to being able to figure out instantly where a person is from merely from looking once. Your father is from the Southern Water Tribe. You however, I cannot place you. Where are you from?"

Finally Ben understood. His appearance must've been such an anomaly for Azula that she had become fiercely curious. He had seen many humans who had resembled certain races in this world. Katara and Sokka definitely looked like inuit people. Toph and Jin looked like they could be chinese. Azula herself seemed to look Japanese (even though it was tough to tell the difference for Ben). But he had not seen a single American-looking person or European type ethnicity the entire journey.