W Def and M def after Big Bang?

Doing a bit of research, there are about 100 mobs which have higher Magic Attack values than Physical Attack values. Of these, the average increase is less than 100. Many of the outliers are major bosses (Horntail, Pink Bean Statues) for which the required HP value is already known. One of the areas which I did not check are Magic Attack values that are associated with specific attacks. Some attacks have their own magic attack damage that override the default magic attack given to the mob.

In short, if you have enough HP to take touch damage from a mob, chances are very good that you can take a magical hit from it as well.