Normal fire magic has a casting range of the caster's "Spirit" attribute value times ten, plus any additional enhancement provided by magical items.
However, the casting range of Explosion Flame Magic is generally only about one third of a wizard of the same level.
Although the Eighth Ring Flame Bull Wizard before us appears formidable, he actually has "short arms," with a range of only about 1000 meters.
And this 1000 meters is the maximum range.
Within 0 to 200 meters, the power of Explosion Flame Magic does not diminish.
From 200 meters on, all the way to 1000 meters, the power of Explosion Flame Magic rapidly declines, eventually dissipating into nothing at the 1000-meter point.
As long as the distance is well managed, Noland Lee believed he could use a "kiting" strategy to take down the Flame Bull Wizard.
It's probably also because he knew his casting range was limited that the Flame Bull Wizard rushed up to Noland Lee before threatening him.