Sol Badguy's signature weapon and his creation. Also known as the Fuuenken (封炎剣) and a part of the OutRage, it allows Sol to use his fire powers to the fullest. It was originally owned by the Sacred Order of Holy Knights for safe-keeping and was “stolen” by Sol Badguy when he deserted the organization (though Kliff Undersn intended to give it to him from the start.) The theft of the Fireseal is one of the reasons of Ky Kiske's animosity towards Sol Badguy.
In Overture, Fireseal seems to have been heavily modded by Sol and its appearance changes considerably.
- Fuuenken can be seen on the table at Arakune's Gag Ending in the game Blazblue: Continuum Shift.
- The overall design of Fuuenken is based upon a gas lighter.
- A weapon similar to Fuuenken is the Aztec Macahuitl.