Sorcerous tools of flame are not just about raining fiery death upon your enemies. They also are about taking the fire magics you already wield with great confidence and fury and making them more versatile!
Rod of the Fire Tendril
Rod, rare (requires attunement)
This wooden rod is carved in a winding spiral pattern, resembling nothing so much as a desiccated monstrous tentacle. The rod is unharmed by fire, and as a bonus action you can command the rod of the fire tendril to burst into flame equivalent in all ways to a torch. If wielded as a club, the rod is a magical weapon and deals 1d6 fire damage to the target on each hit.
The rod’s primary power is to alter the shape of your fiery magics. When casting a spell that affects an area at least 10 feet long or wide and deals fire damage, you can convert the area of that spell into a line 20 feet long times the spell’s level. This line is 5 feet wide and 5 feet high, but it need not be a straight line. You can shape the line however you wish up to its maximum length, as long as each square of the spell’s effect is contiguous (including diagonally) with the previous square as you trace the spell’s path. You can overlap the spell’s area through squares it has already filled, but creatures in any part of the spell’s area are affected only once by it. This altered spell area is stationary even if the spell’s normal area can be moved, such as an incendiary cloud.
After using the rod’s power to alter a spell’s area, you must complete a short rest before you can use that power again.