[1.2.300] New Class?

Well first of all, an equip that doubles your defense would be ridiculous in Nexon's mind.

Second, just doubling defense doesn't fix anything. If you have 700 def you're not really going to be taking that much more damage than if you had 1400 because defense by itself doesn't reduce damage by enough.

I'm not sure how defense works, but imagine defense makes you get hurt with 1 less hit point per defense. If you double that up, it's like having your defense gear turned to hp gear. Only stacking with pots.

Of course, I have no idea, just thinking an aproximate.