"Kerberos" is used rather than "Cerberus" because Japanese transliteration of Greek goes off the actual Greek, rather than the Anglicised bastardisations.

Hence, Cerberus is pronounced with a hard K, and "titan" is pronounced TEE-tahn instead of TY-tan.

bongani said:
"Kerberos" is used rather than "Cerberus" because Japanese transliteration of Greek goes off the actual Greek, rather than the Anglicised bastardisations.

Hence, Cerberus is pronounced with a hard K, and "titan" is pronounced TEE-tahn instead of TY-tan.

*Latinized bastardization.
Latin spelled most of the words it stole from Greek that had a hard K with a hard C, instead. At some point, the o morphed into a u (maybe to make it a neater Second Declension noun? I dunno.), but you'll find both spellings in Latin sources.
That means a bunch of formerly Roman territories all spell Cerberus, and a bunch of other Latinized Greek loan-words, with a soft C/hard C instead of a K, and with a -us instead of an -os. Cause that's how the ole Romans did it.
Like, it's Cerbère in French, Cerbero in Italian, Cerber in Polish, and Zerberus in German. That last one's a bit wild, but it still follows the Latin form.
So we can blame the Romans (as we can for so many things), and then about fifteen hundred years of phonetic drift.