User blog comment:Purehito/What is your favourite magic and what magic would you like to see in the next FT arc?/@comment-7888801-20130628002117/@comment-7418318-20130628080502

I don't think Ivans illusions are allmighty. If they used an item strong enough to really take out Laxus, I'm pretty sure that it's magic power would be too much to be masked completely.

And Ivan seemed very convinced that the people he brought along are more than enough to deal with Laxus, so as FTGM already said he most likely didn't think he'd need any extra insurance.

But in Ivan's place I would have let Kurohebi copy Obra's magic, to make sure that Laxus magic is sucked out, or let him copy some other more usefull magic rather than Max' sand magic.