A double-bladed sword, also known as a double-edged sword or a twin sword, is a weapon that features a blade on both sides of the hilt. While they can be visually striking and intriguing, double-bladed swords are not commonly found in historical records or practical combat applications. There are a few reasons for this:

1. Balance and Control: Double-bladed swords tend to be more challenging to balance and control compared to single-edged or single-bladed swords. The weight distribution and handling characteristics of a double-bladed sword can make it unwieldy and difficult to maneuver effectively in combat.
2. Edge Alignment: With a double-bladed sword, maintaining proper edge alignment becomes more challenging. It requires precise control and coordination to strike effectively with both edges simultaneously or to switch between the edges quickly. This can be cumbersome in combat situations.
3. Defensive Limitations: Double-bladed swords offer limited defensive capabilities compared to other sword designs. With two sharp edges, parrying or blocking an opponent's attack can be more challenging, as there is a risk of the opposing blade sliding along one edge and striking the wielder.
4. Specialized Training: Effective use of a double-bladed sword would require specialized training and mastery of unique techniques. The average swordsman or warrior might not have the time or resources to develop the necessary skills for this specialized weapon.

While double-bladed swords have been depicted in various fictional works and video games, their practicality and effectiveness in historical or real-world combat scenarios are questionable. Most historical swords and weapons are designed with a balance of offensive and defensive capabilities, taking into account factors like weight, maneuverability, and practicality on the battlefield.