I would like the same question answered since am exactly at the same predicament.

On the last boss in Chapter 13 and keep dying...can anyone tell me who/what roles they used to win?

I have like 8k HP for all my characters and I still die...I swear the English version seems cheaper. I always get killed when the boss has like no HP left, I get attack spammed.

I used Lightning, Fang, Vanira with Blaster, Jamar, Jamar and Healer, healer, Defender Attacker Blaster Attacker and Blaster, Blaster, Attacker.        

they made that you cannot preemptive stike the Ochu. instead of taking 26 seconds to beat  it, it takes over 3 minutes now. i cannot imagine how long it will take to max all characters that they changed this.  ( if they didnt change it would take about 15 hours to fully max every character) 

i used fang, lightning vanille. i used jammer healer jammer, after i casted all the debuffs, deprotect, deshell, slow, imperil, and poison. i switched to attacker blaster blaster, then when he had about half life, i used highwind and then switched to jammer healer healer, after i healed, switched to jammer healer jammer.  repeatt the debuffs, and i used techiques when he casts the status effects. he should go down in about 2 minutes. 

Okay, thank you guys. I'ma try that now and hopefully I win!!!

Mission 7 keeps kicking my ass :(

King Behemoth's - Fuck You.

Die.

Now.

Bastards.

(Sorry for language. But this rant was needed.)

how many stages in the crystarium? and why the fuck does the last 3 roles everybody learns have insane amount of CP reqiured i saw up to 24k!!!! i might just focus on everybodies original 3 is that enough?

You get level 5 Crystarium after you kill the Final Boss. Every characters non-main roles cost double the CP.