beautiful, handsome, elegant
姱 centers on physical attractiveness and grace: beautiful, handsome, or elegant in appearance.
姱 combines 女 (woman) with 夸, which likely contributes the sound and may relate to the idea of beauty or elegance. The exact historical development is uncertain.
A woman (女) beside 夸, which looks like a person standing tall and proud, suggests a beautiful, elegant figure.
For カ, imagine a beautiful woman driving a car: car -> カ, and her elegance makes the car shine.