With the Dust Vultures currently targeting those from the dark guild, they form a circle around those building. No doubt that they can differentiate those who capture them and those who were not involved, but that's only applies to some of the intelligence among the flock, even that won't cut it as their power will still affect those who around them meaning the soldier, the adventure and the captured person that will be sold will also bite the dust. Furthermore, the king of the flock is easily a B rank monster and with a flock of this size, they are usually considered as an A rank threat for the adventure guild. What's more, there have been a documented case of a flock of bird easily destroying a number of major city in the past in one week period, gaining themselves an S rank threat by guild standard. 

Knowing this, Azumi have no choice but to leave and took care of the dust Vulture, considering that some of the little dust Vulture that have escaped, it's obvious that they don't belong to the group that is right Infront of him, this make the situation better and worse at the same time, as the number of those bird that he have to fight decreases but leaving them as they are will cause another problem as they can destroy home and kill other residents. That's why Azumi send Aqua, the highest ethos of the water element to go and suppress them while he will take care of the flock

He start of by chanting a thunder and ice magic simultaneously toward the flock of bird, but the king of the flock seem to command the group to create a dust wind barrier to dampen the impact of his magic. 

(Smart but that won't be enough) [Azumi]

He then begin to gather around a large number of mana and release several ice arrow toward the flock continuously, little by little withering down the defense of the flock until the vulture in the periphery start to get injured one by one. As a countermeasure, the flock begin to release stone made using magic at Azumi. Azumi simply use wind barrier to shield himself

(This will be over if I keep on doing this) [Azumi]

As he doesn't see the need of changing his strategy, he simply continue to fire off the ice arrow magic, couple with the fact that this is still in the month of snow, his ice magic power become more powerful. Just as he is about to increase the number of ice arrow, he sense something

(This is, the king is activating dust and avian terrain!) [Azumi]

As soon as he detected that, a mini sandstorm come to greet the people of Mesembryanthemum and a green wind Like zone can be seen protecting the vulture in the flock. While not as powerful as the attack of the dust bird, the mini sandstorm is still an extension of the flock power, thus the building surrounding the flock begin to slowly turn into a dust and the people inside of the building begin to have symptoms of irritation of skin, with some having their finger slowly turn into a dust. Even Azumi himself start getting affected as some of the sandstorm particle manage to bypass his neutral mana shield surrounding his body, thus irritate his skin

"Aqua!" [Azumi]

"Got it!" [Aqua]

Both Azumi and Aqua start their chant

""Oh water that cover the entirety of the earth, surround us and empower us, Water terrain"" [Azumi, Aqua]

With both of their power combined, a huge sphere of water encased not only the flock of bird, but also encasing the dust terrain of the flock. With this, the sandstorm won't endangered the resident

"Aqua, please maintain the terrain" [Azumi]

"Got It!" [Aqua]

"Oh, how about the other dust vulture?" [Azumi]

"I have drown and dissolved them in an acidic liquid" [Aqua]

"That's pretty brutal" [Azumi]

With the little chat done, Azumi begin to use ice and water arrow. Since he is surrounded by the water terrain, his water magic boost significantly and by extension his ice magic

(Since the sphere is wide enough, I could attack them from all directions) [Azumi]

With that, he make the ice and water arrow from all the direction of the flock. As a last resort, the king of the vulture flock try to directly attacking Azumi but

"Getting desperate huh..." [Azumi]

(Well, the king do have a sharp instinct in the first place as it can gauge my strength, so to attack right now just prove that it knew what will happen) [Azumi]

Azumi simply use a large water and ice magic and shoot it directly to its head, finishing the king in a single blow. Once the king have fallen, the subject follow as Azumi simply continue his barrage of magical arrow until there's no single dust vulture left. He then summoned Aqua

"Aqua, can you dissolved the dust Vulture without affecting its magic core" [Azumi]

"Sure, leave it to me!" [Aqua]

"Thank you" [Azumi]

With that, he manage to prevent worst case scenario from happening