Necro thread or not, that's still a valuable question that could have been answered...

The def buff on the enemy can be easily removed with a dispel (That shouldn't be an issue for light users, considering Sol is the N°1 kamihime to get for a light team.)

Also, this buff is less crap than people might think in the first place. It can be used to slow down your damage if you don't want to push a boss in rage phase too soon. I use it this way during accessory quests and i barely have any raging overdrive on the last boss.

If you're not running any dispel, you can still use it just before killing the last enemy of a wave. This way you'll have a 2 turns def buff for the wave after. Not that great but better than nothing.