Does this list of questions apply to the Gym Leaders, or everybody? If everybody, then here is mine for Trevore.
1. "Outside of battling, I lead the Black November cult, which in turn leads the Grunts of Team Ultima. Basically, I'm the Vice Leader of Team Ultima. However, when I'm not focused on the Overlord's plans, I am tracking down Arceus, for reasons of my own..."
2. "How weak. I would utterly destroy that trainer's Rattata, regardless of its level."
3. "I would tell him that he needs to learn how to battle, or in the end, he would get walked on. As an invitation, I would have him join Team Ultima as a grunt."
4. "How foolish. A mere child, thinking that after winning against me, he has the right to act like he's the king of this region? Such idiotic words will have him getting killed. I'll let him live... for now..."
5. "My favorite season? Why, it's simply Autumn. Something about that chilly breeze, mixed with leaves falling from the trees, just calms my nerves. Why, the month November is during that season as well, and I was inspired to form the Black November."
6. "I happen to enjoy all of the types of music equally, but I enjoy Alternative Rock much more. I also enjoy Classical music as well. However, if there's one type I don't like as much... It's Country. Why do I hate Country? Because all it seems to be about these days are trucks, women, breakups, and other sorts of ridiculous nonsense."
7. "Strength is one of the necessities to ultimate power. The other, is Knowledge. When both qualities are used, ultimate power can be reached."
8. "Oh dear... A city that is under attack by terrorists! Whatever shall I do? Why, you don't seem to understand, my friend... I am leading the attack. Why would I have to give into my own demands, when I'm leading the attack?"
9. "Love is weakness, and only for the foolish. It stirs the minds of many, thinking that there is hope, but all hope is gone, burned away, destroyed into nothingness. However, if you truly must know... All I must say is that past has burned away many years ago."
10. "Your offer of battling will only lead you to your own demise. Prepare to lose all hope, and watch as your world around you shatters before your very eyes."
Some of this applies to my eventually made backstory a little bit, such as 9, but not so much. My character is actually my player character from when I played Rejuvenation and Reborn, but many years later after Reborn, as a villain, rather than a good guy.