[1.2.314] Battlemage Job

I don't understand Blue Aura. I personally don't see it being useful for an MMO like MapleStory where the monsters and bosses hit EVERY person in the range of the attack. In a different type of game where the monster or boss targets a specific person and can only attack them (which is where the real tanks come in), I could see that being useful for when the monster or boss targets a non-tank player.