暗い火事 (kurai kaji) would mean "Dark Fire" in Japanese.
Improvement:
火事 (kaji) means fire, but in a different sense than the element 'fire' itself.. it's used when E.g you say 'The fire burnt down the building'.. in a meaning of 'conflagration'.
暗い火 (kurai hi) is more suited for 'drak fire', since 'fire' means 'flame, blaze' here.
Azaki
kuraihana
kuraikokoro
kuraitaiyo
The phrase 'dark storm' would be 暗い嵐 (kurai arashi) in Japanese.
moeteiru
Azaki
kuraihana
kuraitaiyo
kuraikokoro
ダークデーモン
The phrase 'dark storm' would be 暗い嵐 (kurai arashi) in Japanese.
meinu
kurai mori
'kurokute utsukushii'.
kurai harouiin
Japanese is the official language of Japan, spoken by almost all of its people. The translation of dark spirit into Japanese is kurai seishin.