It’d be closer to Lycus/Lykos.
ヒュプノス ("Hyupunosu") -> Hypnos
チュポン ("Tyupon") -> Typhon
デュナミス ("Dyunamisu") -> Dynamis
I'd assumed it was リューコス, which would make a stronger argument for "Leukos/Leucos", but it turns out it's リュコス, which follows the pattern above ("Lykos/Lycos").
(And yes, most people would romanize it as "Chupon", as per FFVI, but I went with "Tyupon" just to make the pattern more clear. As for Ultros/Orthros, I've long since stopped freaking out over that, especially considering the real
Orthrus was Cerberus' two-headed little brother, not a talky octopus. ^_^;)