Disgea 4 confused, HELP ? (noob question) First game i have played of the franchise, so far it seems to be to my liking, but i have 1 small problem. **Is the game suposed to be this difficult ?**

Played through to Emizel boss fight, doing every level just 1 time. Every fight my char die ( mostly always the 3 monsters and the red mage ). Now during the Emizel fight ALL of my char died except Fenrich and cleric ( because he could generally 1 shot, sometimes 2 shot my heroes). 

In SRPG games, I generally think, that if smb dies, i failed at playing the game how it was supposed to be played.

**The questions :**
So, what is my problem ? Am i failing to utilize in game mechanics ? Is unit diening a lot suposed to be normal ? Am i suposed to play every level 10 times to level up ?