Combating Blades

King's Wrath was a deadly two-handed sword forged for the royal family of Magnerii, to be used by the current ruler. The sword became unnaturally light in the hands of one with royal blood, and was unnaturally heavy to anyone else. Flames flickered along the blade when an enemy was near, and skill came naturally while wielding it. It could cut through armor and flesh like butter, and could deflect any kind of attack, magical or physical.
King's Bane was created to counteract King's Wrath, and was designed specifically with kingslaying in mind. It had all of the abilities that King's Wrath possessed, except instead of flames, electricity would spark along the blade in the presence of royalty.
When both weapons were near each other, King's Wrath gained the ability to conjure fire, and King's Bane gained the ability to conjure lightning.