taru-adjective, adverb taking the 'to' particle
Literary or formal word describing intense, passionate, or vehement states, often used in written descriptions of emotions, arguments, or natural forces. Functions as a taru-adjective or adverb with と.
Everyone was overwhelmed by his fierce fighting spirit.
The violently blazing flames dyed the night sky red.
Standard kanji spelling using the iteration mark 々.
Variant spelling without the iteration mark; less common but equally valid.
Reduplication of 烈 (retsu, 'fierce, violent') for emphasis. The exact historical derivation is uncertain, but the form follows a classical pattern of doubling a kanji to intensify meaning.