at level 45 or so with six jobs mastered you shouldn't have any trouble with any of the bosses in CoD (besides Omeag and Shinryuu of course). Exdeath is definitely beatable at that level assuming you know the basic boss battle strategies and know what you are doing. If you can't beat NeoExDeath any other way, you should just use Coin Toss. As a matter of fact, you should use Coin Toss anyway. And also, Samurai is one of the best job classes, between good attack, great evade, good equipment, and coin toss.