Ouch! Nogi seems to get hurt a lot.  Such is the life of a Defender.  You need to be in the front line protecting everyone else, but no one is there to protect you.  They usually have a high armor class to make up for this, but that can only help you for so long.  Eventually, the enemy is going to get past the armor and slowly grind down your Health Points. The hope is that you'll take down the enemy before they take you down, but if the enemy is equally hard to hit you'll need other people to help you survive.