But not properly. If you've already slapped the usual amount of -Atk on the enemy, you don't get as much gains from +Def.

Also, you can't bring 50 Hime into one fight. You need to pick your abilities, and that means that you effectively avoid +Def whenever you can - so that you can actually useful abilities, such as damage cuts or -Atk debuffs. Only in rare cases like Amaterasu do find yourself with a +Def ability... and even then, it doesn't really do much for you.