Well, on this pic, I drew Jack as an extra character. People liked him. But this is him in one of his moods. This is the darker side of Jack. To be clear, when he's feeling murderous, he's just a little less dangerous than JTHM on a normal day.
Here he is being threatening towards  itsuko103's Lopunny, Foo. In my mind, the dialogue went like this:

Jack: Well, well... if it isn't the little bunny. Hello, little bunny! How are you this fine day?
Foo: Fine, I guess...
Jack: That's good, that's good. Say, where's that bodyguard of yours? The fiery ape?
Foo: J-Jade's doing her homework. Listen, I should really get going...
Jack: So soon? Won't you stay, just for a little match?
Foo: I-I gotta go!

Yes. Those are Jack's clothes laying by him. He's a nudist. Woot. He has an established hatred of Normal-Types. I figured out why he's such a mean-spirited little hobgoblin.