A hot blade is an edged weapon that somehow heats up, adding the thermal energy of its temperature to the kinetic energy of its blow to achieve Absurd Cutting Power. When active, it will usually glow visibly (without losing any of its structural integrity, somehow) because Power Glows. Usually used with swords, but other bladed weapons are also seen occasionally. A subtrope of Absurd Cutting Power. Unrelated to the idiom "like a hot knife through butter"... though hot blades may, indeed, cut through things in such a manner. Examples of Hot Blade include: