The two syllables
赛亚 are the productive 'Saya / Saiah / Saiya' chunk shared across very different name roots:
以赛亚 (Isaiah, Hebrew prophet),
弥赛亚 (Messiah), and
赛亚人 (Saiyan - the alien warrior race created by Akira Toriyama for the manga
《龙珠》 Dragon Ball). The standalone form
赛亚 most often refers to the Saiyans in modern pop-culture use.