Flame Blitz in an Ability in Death's Gambit. Abilities are special skills that can be performed depending on the Weapons you have equipped (much like Dark Souls 3). Ability use consumes Soul Energy, that you get from performing specific actions based on your Class.
Flame Blitz Effect
Dash forward and deal damage to enemies at the end of the dash. Enemies hit set on fire 8 seconds.
How to unlock Flame Blitz