Warrior and Mage at 20.
(Physical something), Archer, Wizard, Cleric at 50.
Holy Knight/Gladiator, Sniper/Assassin, High Wizard/Enchanter, Bishop/Monk at 120.
Paladin at 140.
Samurai, Ninja, Minstrel are special classes at level 100.
Warrior can become:
Holy Knight is a tank, Gladiator is a melee damage dealer with heavier weapons, Sniper is a ranged damage dealer with bows, Assassin is a damage dealer with thrown weapons or spikes.
Mage can become:
High Wizard is a ranged damage caster, Enchanter is a melee caster, Bishop is a healer/support, Monk is a melee caster.
Paladin is a mystery to me, no real info about it.
Samurai is a melee damage dealer, Ninja is a ranged damage dealer, Minstrel is a party support character.
Also, at level 10 you can take an Apprentice class from the NPC in the first town, providing you with basic skills of that class of your choice. These can be swapped between as you see fit.
Mages are weaker on here than other games. I get 1 hit at areas where Warriors can fight at without a problem, getting hit for 250 damage while a Warrior gets hit for 50 damage while I have 280 Hp and the Warrior has 600 Hp. What makes it even worse that I can do 400 damage per cast with the only attack spell, but warriors do 200 damage per regular attack at the same level and can even attack 2-3 times per spell cast. Mages can heal for a lot(I can full heal myself), but it doesn't help when you have 280 hp and get hit for 280 damage. Even if you can heal over the damage, there's a cooldown on spells so you can't recast it to keep alive.
Warriors get +Atk and Double Attack skill at 10, then +Def and a self +Def buff at 20.
Mages get +MAtk, Mana Wave and Mini Heal spell at 10, then +Mp Recovery at 20.
Problem is that warriors don't need the skill because it doesn't do much extra damage and physical attacks are faster, but we have to rely on spells with a cast time, cooldown and Mp cost and we can't learn the upgraded spell or our second/stronger spell for damage. So while we miss out on our strongest early spell, Warriors only lose Provoke which does nothing but make enemies attack them instead. And while Mages need Int for damage and Dex for cast time, Warriors can focus on Str/Vit and get Agi/Dex/Crt when they feel like it.
Turns out Warriors get all their skills, Mage's final skill is their strongest attack which... isn't added into the game yet. I was partying with Warriors 10 levels higher who were doing equal damage to my nuke, and I'm wearing full int items compared to their full def items. So they're built out for tanking instead of damage, yet still dealing high damage. I don't think I'll go much higher in damage within 10 levels.
And it turns out the Warrior +Def self buff is at level 10 instead of 20. Meaning they get an attack skill, +Atk and +Def at 10 where Mage gets an attack spell and heal. The bigger attack spell is in the next patch, as that's one of the next areas supposedly. And the NPC that gives us level 2 of our current attack spell is in the game, but her quest list is bugged and simply displays quit.
Guess the Japanese Wiki has misinformation, Holy Knight = Paladin, there's just something special that happens at level 140 for classes supposedly. Whether it's a skill break level(Unlock a skill on that level) or what is unknown.