Time.timeScale = 0にしたときも動く、WaitForSeconds（Unity）

TimeUtils.cs

using UnityEngine;
using System.Collections;

public class TimeUtils : MonoBehaviour
{
	//TimeScaleに関わらず、指定の秒数まつ
	public static IEnumerator WaitForSecondsIgnoreTimeScale(float time)
	{
		float targetTime = Time.realtimeSinceStartup + time;
		while(Time.realtimeSinceStartup < targetTime)
		{
			yield return new WaitForEndOfFrame();
		}
	}
}

TimeUtilsTest.cs

using UnityEngine;
using System.Collections;

public class TimeUtilsTest : MonoBehaviour
{
	IEnumerator Start()
	{
		//TimeScaleを0にしても動くかどうか確認
		Time.timeScale = 0;
		//3秒まつ
		yield return StartCoroutine(TimeUtils.WaitForSecondsIgnoreTimeScale(3f));
		Debug.Log("TestEnd!");
	}
}

Unity5.3〜 http://blogs.unity3d.com/jp/2015/12/01/custom-coroutines/