The Lion Sword is the fifth primary weapon in Warrior Within.
- "The Lion Sword is a mystical sword that stores energy which can then be released with devastating results. Although this weapon is strong, it takes a decent amount of time to charge it up. During this time, the Prince becomes very susceptible to incoming enemy attacks."
- —Official Booklet Description
This sword gives the Prince the ability to store up energy, and then unleash a more devastating attack. When enemies are hit by these charged attacks, if not dead, is knocked down, leaving them vulnerable.
It was given to the Prince by Kaileena (after activating either the Garden Tower or the Mechanical Tower) and is the sword he fights her with for the first time in the game. The sword is broken after the Prince's battle with Kaileena, forcing him to seek out a new weapon.
- In various pieces of concept art, the Prince is shown wielding the Lion Sword and Eagle Sword at the same time, but this doesn't happen in the game.