Being Reborn means have your current level lowered by 99 and be "birthed" into a particular class. You get to pick a class before being Reborn. You are allowed to be Reborn once you are level 100 or above. The highest non-reborn level which can be attained is 199. If Bursting, the highest level which can be attained is 180. After this level you stop gaining experience from bursting. If you want to level up to 199, you will need to obtain your experience another way, for example, defeating monsters or using capsules.
If you reborn at level 130, you will be reborn at level 31.
If you reborn at level 109, you will be reborn level 10.
If you reborn at level 180, you will be rebirth level 81 etc.
The game looks at your stats: STR and INT. If you have higher STR than INT, then you get to choose between the Melee Professions. If you have higher INT the STR, then you get to choose between the Mage Professions. If you have equal STR and INT, you get to choose your profession (either Mage or Melee) then select the class you wish to Reborn as based on your profession.
When you are reborn, you will receive a Job Manteau which stats are dependent on which level you reborn at.
You also unlock the Job Skill quest when you are reborn. The Job Skill is dependent on which class you have reborned as.
Information about the classes can be seen in the following table:
+10% ATK (without the equipment), decreases target's counter attack rate, and increases a little primary mana ability. Warriors who like to attack will be killers after they're reborn, for them, attack is the best defense. The most important aim for them is to attack the targets quickly and effectively. It will lower the enemies' morale.
+10% DEF (without the equipment), increase a little defense. Warriors are equipped with iron armor and of course agility and speed will be low. But they are good at defense which makes them hard targets to defeat.
+10% SPD (without the equipment), the speed can be increased automatically when they ride a pet without the Saddle. Speed is one of their primary features, though they are also good at riding. They can tame many different pets. In battle, knights are honorable and also they are the indicators of all.
+10% MATK (without the equipment), increases sealed skill a little. The mana attack will be strengthened after being reborn. Furthermore, they are wise and calm enough to create a good strategy, so they are very important in a team.
+10% MDEF (without the equipment), strengthens the resistant ability of the seal, strengthens the resistant ability of mana and physical attacks. They are wise and cannot be disturbed easily. So they can change their wisdom to resistant power which can upgrade their defense and endurance in combat.