Synonyms of hellfire

1 Syllable
dire
2 Syllables
fatal, ruinous, hades, grave, lethal, mortal
3 Syllables
direful, portentous, ominous, under-world, netherworld, baneful, inferno, unlucky, disastrous
4 Syllables
cataclysmic, destructive, calamitous, catastrophic
5 Syllables
apocalyptic, fire-and-brimstone
6 Syllables
apocalyptical