[quote=@ImportantNobody]
It depends on how their illusions work if it would make it impossible for me or not, depending on the character. If they have area of attacks for cheap energy cost they can spam that onto every illusion and hope it's the right one, but if not and they get swarmed by a bunch of illusions and the real one, managing to focus on the real one and defeat them out of the entire group would seem meta gaming so they'd need a way to focus on every illusion coming at them at once.
[/quote]

I feel like illusions should generally come with some type of drawback, or way to know(even if your character can't easily figure it out) that it's an illusion. For instance, even in Bleach, Aizen - a well versed illusion guy - had some fatal flaw that allowed the 4th Captain to figure it out(and also to activate it, you had to have made eye contact with his Bankai).

At high levels, you may not need any significant weaknesses in it, because at that level people will probably be busting out of illusions relatively easily. But at lower levels, there should be some drawbacks.