fast horse, talent
驥 centers on exceptional speed and ability, originally a fast horse and by extension outstanding talent.
驥 combines 馬 (horse) with 冀, which likely contributes the sound and the idea of hope or aspiration, together suggesting a horse of exceptional quality.
A horse 馬 combined with 冀, a shape associated with hope and aspiration, gives the image of a horse that exceeds all hopes—a fast horse and a symbol of outstanding talent.
For キ, imagine a key horse that unlocks victory with its speed: key -> キ, and this fast horse is the key to success.
—