Hit B to swing the fire sword. If you tap Up on the +Control Pad while wielding the blade and then hit B, you'll throw it.”
— Description • Nintendo Power (Volume #134)
Sword of Fire is a Power Combo used in Kirby 64: The Crystal Shards made by mixing the Burning and Cutter abilities. With it, Kirby uses a flaming sword to attack enemies. Kirby can also throw the sword at enemies. The one catch is that when he is holding the fire sword, he can't fly. The sword can be used underwater.
Kirby takes a sword of flame out of his mouth and swings it.