Eh, Turbo didn't do much for me, personally. I feel like because the movie gave him so little screen time, his character didn't leave much of an impact. It seemed like his only personality traits were insecurity, jealousy, and deceit; they didn't give him much room to develop. I might have liked him better if the plot gave him an opportunity to change his ways or show just a hint of internal conflict. But maybe I'm nit-picking. The movie was still amazing, and your art is, too.
He was a villain and had to die, that's Disney's rules. And he pretty much IS King Kandy so he had plenty of screen time and development, he was just in disguise. But I just thought his design was cool and wanted to draw him.
I dunno... to me the king was more of a false persona, not Turbo's true self. To his credit, though, he did convince people in the story that he was a mostly benevolent guy (deception points), but it's just nice to see other sides of villains than only the bad qualities all the time, even if that glimpse only lasts a few seconds. I had no beef with him dying whatsoever.