It's precisely because Jiang Cheng is legendary himself that he understands the inconceivable nature of this technique.
By controlling the Power of Heaven and Earth, he could vaguely perceive the situation in Red Mountain City.
But this perception was not sharp enough.
Even if he could perceive it, if a legendary monster were to appear, he would still be too late to act.
He would have to harness the Power of Heaven and Earth to fly over, then draw his sword, slash, and strike; by the end of this process, a legendary monster could have destroyed an entire wall, resulting in countless deaths and injuries.
The reason he had been able to ride the Two-Headed Flying Dragon to extinguish fires everywhere was because, even if a Fourth-order Boss leapt onto the walls, the army of Red Mountain City would be able to resist for a while.
If the army of Red Mountain City were nothing but a rabble, he, being a legend, still couldn't defend it for long.
