Magic also known as Mana is the source of every Blazers' powers.
Magical power is tied to fate, as such a Blazer's power is fixed from birth and is officially impossible to increase. However some individuals are capable of going through an 'awakening' becoming Desperado's, individuals who have broken the chains of fate, and who possess massive magical power.
A Blazer can use their magic in many ways. Blazers can use their magic to increase their strength and speed by concentrating their magic at the fix part of their bodies, and it varies depending on the amount of magic an individual possesses. Blazers use Mana to power their Noble Arts and can also act as as a barrier. A Blazer constantly shielded with magic couldn't be beaten without an attack empowered by equal magic or more.
There are multiple ways to train areas of one's magic. Shizuku and Nagi trained their mana control by using their magic to mold a special clay. Ikki trained both his mana defense and physical skills simultaneously by balancing atop a sharp tip of a mountain, needing to use his mana defense to prevent getting cut.
Mana Defense: A technique where the user uses their mana to protect themselves from physical attacks. The defensive power and the amount of area covered by the technique varies, depending on the power and control of one's mana.
Mana Emission: A technique where the user releases their mana to accelerate and improve themselves. It's a basic enhancement technique that many Blazers use unconsciously.