Leo felt the hair on the back of his neck rise as he looked up at the towering monstrosity approaching them. He knew that he had to fight but he couldn't see how he could fight effectively at all.
After all, Enkiba was wearing an armor of literal flames! Up until now he had fought with basically his fists in close quarters combat. He glanced back at his companions who were sporting equally concerned expressions.
Luna's magic was essentially Plant based in nature which is extremely weak to fire while Horo's main weapon was a dagger. Yes he could throw and retrieve it but the flames would still dampen his combat ability.
Nyx and Luna were also at a disadvantage but their weapons had a longer reach so they were better off if only slightly.
The only one who wouldn't be affected by that flame armor was Sonata. The issue there was that while Sonata could attack with her Dissonant Shriek and the various applications of it, her mana pool would not be enough to deplete the BOSS's HP.