The way this Build works is that you'll use the Dragon Communion Seal in your right hand to cast spells, because it has better Incantation Scaling at this point in the game, and you'll keep the other Seals in your off hand, rotating them to boost the damage of whichever spell you might be casting. For instance, you'd have the Godslayer's Seal in your left hand when casting Black Flame, and rotate to Frenzied Flame Seal when casting The Flame of Frenzy or Frenzied Burst, and Gravel Stone Seal when casting Lightning Spear.

You'll use The Flame of Frenzy spell on large enemies that don't move to quickly or groups of enemies to take them out quickly. Frenzied Burst is your long range sniping spell that will kill most enemies before they can even react, and charging it makes it go through Shields.

Black Flame is there when you don't need either of these to kill enemies, and will conserve some FP, as well as deal damage over time based on the Max HP of the target. Lighting Spear can be cast when Fire is not a good damage type.

You'll buff with Golden Vow and Flame Grant Me Strength as necessary. Often time you won't need these to one shot most enemies, but if you aren't killing most enemies in one cast then you'll want to use Golden Vow. Use Flame, Grant Me Strength for Boss encounters or tough enemies.