Ok i notice there's 2 types of crit per damage type(energy & attack). Energy crit or energy crit damage%, and Attack crit or atk crit damage%. Which stat is better to stack? The crit damage% or just crit? forgive me if this is confusing....

Crit damage would mean the amount of damage you do on a crit, and stacking normal crit would increase your likelihood to achieve a crit.

But it is a good question.. Not sure. Probably Attack Crit > Attack Crit Damage.

well if your using kaoken wouldnt it be better to stack damage% you think? since kaoken increases crit chance by a lot?

if you using kaioken you must stack crit damage, if you are on places where you cant use kaioken , then stack either attack or critical chance, your choice. Though I'd say, Unless your class has that special effect on skills that increase the damage on 50% if you crit( super kame , giant kame and some others i cant remember right now) you should use increase attack

But do you really want to buy gear based on Kaioken? Like Sabin said what if you are in a place where you can't use it..

If we are talking about base form I would say; stack crit rate.

You'll hit more crits, and they'll still do damage- i'd rather hit 5 crits in 10 strikes, rather than 1 massive crit in 10 strikes.