<p>From the scene (the ending of episode 9), Aizawa noticed the warping of villains immediately, <strong>however,  his main priority were the students who he was responsible for.</strong> 
<a href="https://i.sstatic.net/1jHdc.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/1jHdc.jpg" alt="Aizawa taking charge"></a></p>

<p>He firstly had to alert everyone  because, apparently, no one else noticed until the first batch of villains started to came out. He was also smart enough to call for backup and instruct N0 13 to protect the students right before the decided to engage the enemy.</p>

<p>I'm pretty sure that the element of surprise worked against them, and since he was with a bunch of newbie students, his thought process was much more conservative. </p>

<p><a href="https://i.sstatic.net/uP6aA.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/uP6aA.jpg" alt="enter image description here"></a></p>

<p>A lot of times, while under pressure with little time to react, the best options might not come to our minds until way after such event has occurred. Nevertheless, his call was still very good since his students were his number 1 priority.</p>

<blockquote class="spoiler">
  <p>An example that compliments this; imagine a Samurai fighting while protecting his students compared to that same samurai fighting without any clear distractions. The exact same setting, moreover, you can expect his thought process to be very different in those 2 situationns. </p>
</blockquote>

CC BY-SA 4.0
2019-01-23T16:32:14.093Z
I understand that at the time it may be harder to think of the best solution, but using your quirk when you see danger seems like the most obvious choice. Besides this, he is a professional hero so it seems like using his quirk to protect civilians would be the first thing that comes to mind, since thats the only way he could really protect people.
user30104
CC BY-SA 4.0
2019-01-24T19:54:58.987Z
It seems pretty easy for people to always complain about what could and could not have been done. And sincerely speaking, I also do sometimes, but you'll be surprised how different situations make people act differently. I do agree that he could have ended the situation immediately, but then if that had happened, would we have actually enjoyed the arc as much? Most animes would usually tend to prolong it quite a bit and that dynamic is also a factor. Because lets be honest here, things don't always go the way we'd expect them to @user30104
Rumpelstiltskin
CC BY-SA 4.0
2019-01-24T20:12:32.443Z
I guess we could coin it as an error on erasers part, or a plot convenience for some splice of action, either way, both are justified. @user30104 Even police officers and judges make mistakes that could negatively affect innocent people, despite the huge amount of experience, and its actually relatable in a sense. We are NOT PERFECT and on a daily basis, the mistakes we make surely proves that. It could also have been more of plot convenience, to make the story-line more interesting and longer.
Rumpelstiltskin
CC BY-SA 4.0
2019-01-22T02:36:16.573Z
2019-05-31T23:53:57.740Z
2019-05-31T23:53:57.740Z
Rumpelstiltskin
<p>Because he want actually visible yet for Eraserhead to actually see in order to use his quirk on him. When the villains started warping in, it was just a portal, not actually Kurogiri himself. He didn't show himself to the students and 13 until Eraserhead had already jumped down the stairs to take on the mob in the plaza. So Eraserhead probably wasn't even aware of his presence until after Iida had escaped, had dealt with 13 and joined Shigaraki and the Nomu in the plaza. Eraserhead would not have been able to lay eyes on him until at least this moment anyway.</p>

CC BY-SA 4.0
2020-10-19T00:15:21.497Z
+1 i really like this answer, its possible he could not directly tell whose quirk it was, although in both anime and manga kurogiri's form was still visible as the core of the portal, but yea considering the element of surprise and how quickly villains began to flood in, it makes sense that past the portal opening it would be difficult to pinpoint the quirk user
Rumpelstiltskin
CC BY-SA 4.0
2019-10-06T01:43:04.120Z
2019-10-06T01:43:04.120Z
DrOblivian
<p>Eraser noticed pretty quickly that someone was warping in so why didn't he cancel out Kurogiri's quirk as soon as he saw him and take him out when there was only one or maybe two of them? He and Thirteen shouldn't have had much of a problem fighting two villains when only one has a power, and he noticed almost immediately that something was wrong.</p>

<my-hero-academia>
Why didn't Eraser Head just cancel out Kurogiri's quirk when he attacked the USJ?
# Why didn't Eraser Head just cancel out Kurogiri's quirk when he attacked the USJ?
Posted by: username_0 on 2019-01-21
Eraser noticed pretty quickly that someone was warping in so why didn't he cancel out Kurogiri's quirk as soon as he saw him and take him out when there was only one or maybe two of them? He and Thirteen shouldn't have had much of a problem fighting two villains when only one has a power, and he noticed almost immediately that something was wrong.
**Tags:** my-hero-academia
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## 2 answers
### Answer by username_1 on 2019-01-22. Score: 3
From the scene (the ending of episode 9), Aizawa noticed the warping of villains immediately, **however, his main priority were the students who he was responsible for.**
[![Aizawa taking charge](https://i.sstatic.net/1jHdc.jpg)](https://i.sstatic.net/1jHdc.jpg)

He firstly had to alert everyone because, apparently, no one else noticed until the first batch of villains started to came out. He was also smart enough to call for backup and instruct N0 13 to protect the students right before the decided to engage the enemy.

I'm pretty sure that the element of surprise worked against them, and since he was with a bunch of newbie students, his thought process was much more conservative.

[![enter image description here](https://i.sstatic.net/uP6aA.jpg)](https://i.sstatic.net/uP6aA.jpg)

A lot of times, while under pressure with little time to react, the best options might not come to our minds until way after such event has occurred. Nevertheless, his call was still very good since his students were his number 1 priority.

> An example that compliments this; imagine a Samurai fighting while protecting his students compared to that same samurai fighting without any clear distractions. The exact same setting, moreover, you can expect his thought process to be very different in those 2 situationns.
> **Comments:**
> **username_0** (2019-01-23): I understand that at the time it may be harder to think of the best solution, but using your quirk when you see danger seems like the most obvious choice. Besides this, he is a professional hero so it seems like using his quirk to protect civilians would be the first thing that comes to mind, since thats the only way he could really protect people.  
> **username_1** (2019-01-24): It seems pretty easy for people to always complain about what could and could not have been done. And sincerely speaking, I also do sometimes, but you'll be surprised how different situations make people act differently. I do agree that he could have ended the situation immediately, but then if that had happened, would we have actually enjoyed the arc as much? Most animes would usually tend to prolong it quite a bit and that dynamic is also a factor. Because lets be honest here, things don't always go the way we'd expect them to @user30104  
> **username_1** (2019-01-24): I guess we could coin it as an error on erasers part, or a plot convenience for some splice of action, either way, both are justified. @user30104 Even police officers and judges make mistakes that could negatively affect innocent people, despite the huge amount of experience, and its actually relatable in a sense. We are NOT PERFECT and on a daily basis, the mistakes we make surely proves that. It could also have been more of plot convenience, to make the story-line more interesting and longer.  
---
### Answer by username_2 on 2019-10-06. Score: 2
Because he want actually visible yet for Eraserhead to actually see in order to use his quirk on him. When the villains started warping in, it was just a portal, not actually Kurogiri himself. He didn't show himself to the students and 13 until Eraserhead had already jumped down the stairs to take on the mob in the plaza. So Eraserhead probably wasn't even aware of his presence until after Iida had escaped, had dealt with 13 and joined Shigaraki and the Nomu in the plaza. Eraserhead would not have been able to lay eyes on him until at least this moment anyway.
> **Comments:**
> **username_1** (2020-10-19): +1 i really like this answer, its possible he could not directly tell whose quirk it was, although in both anime and manga kurogiri's form was still visible as the core of the portal, but yea considering the element of surprise and how quickly villains began to flood in, it makes sense that past the portal opening it would be difficult to pinpoint the quirk user  
---
