Angel's method was to use "Exile" to banish the foul black mist into the void.
This was also typical wizard thinking.
To wizards, whenever they encountered something dangerous, highly poisonous, experimental waste, or even undead, as long as they found it troublesome to clean up, they would use Exile.
Angel's first thought had naturally been Exile as well.
But when Angel actually tried to put it into practice, he realized he had been overthinking things.
In reality, he could open Exile Space at any time through Exile. But now that he was in the Mirror Realm, he used every means at his disposal and still could not find the entrance to Exile Space.
In the end, Kuntela helped open a spatial rift.
According to Kuntela, the other side of the rift was the void corresponding to the Mirror Realm... but it did not know exactly where in the void it led.
That was fairly close to the concept of Exile. Exile also banished things into an unknown void.
With this spatial rift, Angel had something to make up for it. He silently manipulated the power of wind, guiding all the foul black mist into the rift.
It took nearly twenty minutes before the foul mist on the first floor had completely vanished.
Though the mist was gone, the stench left in Rock Hall did not immediately dissipate. Still, it was much fainter than before—faint enough that an ordinary person could endure it with a mask on.
As for Angel and the others, they naturally had no need to endure it. They simply put up a Purification Field and entered Rock Hall again.
The main reason they had to return to Rock Hall was... the Mystic Ritual Box was still inside.
Although the Mystic Ritual Box had mutated the first time