Think about your favorite characters in literature. Katniss Everdeen. Sherlock Holmes. Atticus Finch. These names aren't accidental. They evoke specific feelings. "Katniss" feels sharp and organic, like the plant she’s named after. "Atticus" sounds ancient, stable, and wise. If Atticus Finch was named "Johnny Speed," the entire tone of To Kill a Mockingbird would shift into something unrecognizable.
Our brains are hardwired to make associations with sounds. This is often called the "Bouba/Kiki effect," where certain sounds are perceived as "round" and others as "sharp." When you're brainstorming, you need to decide: is your character a Bouba—soft, approachable, comforting? Or are they a Kiki—jagged, energetic, and perhaps a bit dangerous?