Blazeblades are a type of Angelus weapon.
Blazeblades, when inactive, are just an ornate hilt.
When activated, a powerful magnetic field is generated. This is then filled with plasma, so densely that it behaves as a solid. As such, this weapon can cut through even the hardest conventional materials, including blackmetal.
The blade comes from and goes into the hilt at great speed, so the wielder can kill an opponent by releasing the blade when the hilt is still at distance.
They are similar to Blueblades in that they use temperature to their advantage. However, they can also block and deflect charged weaponry.
The more powerful Angeli have more powerful and ornate Blazeblades, which can in some cases block Plasma Beams or other weapons.
These are also often upgraded to be able to fire plasma at targets with great speed, enabling ranged combat.