There are three oriental-based classes to Oblivion, each with a specialization (
Combat,
Magic and
Stealth):
Class: Ninja
Best Race: Argonian, Bosmer, Dunmer and Khajiit
Best Birthsign: Any that you want, but Steed, Thief, Shadow or a birthsign that increase your magicka seems to be best choices
Specialization: Stealth
Attributes: Intelligence, Speed
Major Skills:
1. Illusion
2. Blade
3. Marksman
4. Security
5. Sneak
6. Light Armor
7. Speechcraft
Description: Stealth warriors that use illusion tricks to confuse the enemy and ranged and blade attacks to kill the enemy. Also, they are honored warriors.
Combat Purposes: Since they have Blade as major skill, they will use blade weapons (daggers, short blades, long blades) to kill a enemy. They have also Marksman weapons to help them (but Marksman is a Stealth skill). To other combat purposes they do not have much use.
Magic Purposes: Ninjas have Illusion as major skill, so, a Ninja character can use a lot of spells to trick the enemy, or Paralyze spells to paralyze the enemy, and kill the enemy with a ranged weapon or a blade. This trick can be useful to train Marksman and Blade weapons. To other magic purposes they do not have much use.
Stealth Purposes: A ninja character has a lot of stealth purposes. First of all, stealth is the specialization of a ninja. Second, the Ninjas have Light Armor skill (to protect them), Security to open locks, Sneak to be not seen (combined with Chameleon spells, this can be a very useful trick). Also, the Ninjas has Speechcraft, to help them to "honestly" kill a person and raise their disposition.
Other Skills: To ninja... Other useful skills can be Athletics and Acrobatics (to help them with adventures). A ninja don't have a lot of tricks that don't involves stealth skills or Illusion spells.
Usefull Factions: Thieves Guild and Dark Brotherhood. If you have a mod that adds a stealth-based faction, this will be also very useful.
Roleplay Restrictions: Ninjas can make very stealth-based useful characters, with Illusion mage powers, and a Combat skill (blade). With tricks that can help (such as combination of Chameleon and Sneak, paralyze and attack with ranged weapons), Ninja is a very fast and agile character (perhaps more than any other type of Stealth class).
Ideal Mod(s): A mod that add a Ninja Armor (and an Asian Race, if possible), to your character resembles a ninja.
Class: Samurai
Best Race: Imperial is the best, but Nord, Orc and Redguard also make great Samurais.
Best Birthsign: The Warrior or a birthsign that increase your Magicka.
Specialization: Combat
Attributes: Strength, Personality
Major Skills:
1. Speechcraft
2. Restoration
3. Blade
4. Marksman
5. Mercantile
6. Heavy Armor
7. Armorer
Description: The samurai are honored warriors that are strong and fast, but if they lose the honor they do a ritual named "Harakiri".
Combat Purposes: The samurai has a powerful blade skill (that let the Samurai use the most powerful blades), combined with their heavy armor and armorer. Also, with Heavy Armor, the samurai has the best protection (with the best armor, in case, Daedric), best than Ninjas. With their armorer skill, the samurai can repair an armor or weapon in darkest hours.
Magic Purposes: The samurai don't have much magic purposes. But, with Restoration spells, the Samurai can restore their health and fatigue in the darkest hours, and restore their damaged attributes (this can be very useful if your character has a damaged strength). Also, a Samurai can cure himself from poison and diseases, and absorb the enemy's attributes, skills, health, magicka and/or fatigue.
Stealth Purposes: The samurai don't have much stealth purposes. But, the samurai has the Speechcraft skill, that can help himself, increasing the NPC disposition, and/or taunting them to kill them). And the Mercantile skill, that allow them to get best prices in armor/weapon/restoration spells, training, and investments. But these stealth purposes are more personality-like than agility and speed. The only other stealth purpose that a Samurai has is the Marksman skill what allow the samurai to use ranged weapons.
Other Skills: Other combat skills (blunt and hand to hand): If you can train them, you will get more combat options apart from Blade.
Usefull Factions: Fighters Guild.
Roleplay Restrictions: The samurai, depsite having Combat as specialization, has few Combat tricks. The only offensive Combat skill that a Samurai has is Blade. But, Restoration, Speechcraft, Marksman and Mercantile can help the Samurai so much that other Combat skill will be not necessary. Samurai can be considered a improved version from Rogue.
Ideal Mod(s): A mod that add a Samurai armor...
Class: Zen Master
Best Race: Altmer or Breton, but Breton is best. Female Argonian also can make great Zen Master.
Best Birthsign: Any that increase your magicka. The Atronach is best.
Specialization: Magic
Attributes: Willpower, Endurance
Major Skills:
1. Hand-to-Hand
2. Restoration
3. Destruction
4. Mysticism
5. Speechcraft
6. Sneak
7. Alchemy
Description: The zen master is a teacher of the art of Zen Buddhism. They have the highest willpower, and don't make any thing that their religion don't allow. Also, they are against violence.
Combat Purposes: The only combat purpose that a Zen Master has is the skill Hand-to-Hand. Whereas that "they are against violence", they don't have any combat purpose apart from defending themselves with their own hands.
Magic Purposes: The Zen Master has a lot of magic purposes. First, they have a lot of magic skills that can damage the enemy and restore their attributes and skills. Alchemy also help to create potions with benefities from all Magic skills (except Conjuration, and including the skills that Zen Master don't have as major skills, in other words, Illusion and Alteration).
Stealth Purposes: The Zen Master don't have much stealth purposes. The Speechcraft skill can help, taunting and/or admiring NPCs. And the sneak skill can help them (if you combine Chameleon that you get from a Potion with Sneak mode, you will get a Ninja trick).
Other Skills: If you can train Illusion and Alteration, you will be a "Mage" with great Sneak, Speechcraft and Hand-to-Hand skills.
Usefull Factions: Mages Guild.
Roleplay Restrictions: The Zen Master, of all oriental classes, is the more focused in its own specialization. Also, since you only have the Hand-to-Hand skill to help you if your Magicka ends, you don't need to carry a lot of things (armor and weapons). This allow you to carry a lot of artifacts that you can sell to get rich. But the disadvantage is that you will don't have a armor skill to protect you (Light and Heavy armor are stealth and combat skills, respectively, and Unarmored skill don't exists in Oblivion).
EDIT: TO add more oriental-based classes
Class: Snake Charmer
Best Race: Altmer or Breton
Best Birthsign: Any that increase your magicka
Specialization: Magic
Attributes: Intelligence, Personality
Major Skills:
1. Conjuration
2. Blunt
3. Alteration
4. Mysticism
5. Restoration
6. Mercantile
7. Light Armor
Description: The Snake Charmer is a person who uses a flute to hypnotize a creature. They have high experience in conjuration and mental control of a creature, by playing a music.
Combat Purposes: Not much. The only combat purpose that a snake charmer has is to defend himself using blunt weapons, in cases that his magicka ends.
Magic Purposes: The snake charmer don't have Destruction as a major skill. This is reimbursed by Conjuration (summon a creature to defend you, then attack the enemy with Blunt Weapon), "Absorb" restoration spells (when you absorb the foe's health you also regenerate your Health) and Blunt (use blunt weapons to hurt the enemy). The snake chamer has Mysticism as major skill, this allow you to use the "Soultrap your own summoned creature" trick, and you can enchant your Blunt weapons and light armor pieces. With Alteration, you can "burden" the enemy and "feather" yourself, open and lock doors, protect yourself and walk/breath in water.
Stealth Purposes: Apart from Mercantile effects (get best prices in armor, weapons and spells, invest), and defending yourself with light armor, you don't have much stealth purposes.
Other Skills: If you train Destruction, you can use damage spells to hurt the enemy, but this is unecessary.
Usefull Factions: Mages Guild
Roleplay Restrictions: The snake charmer is a useful character to players who love have a creature as partner. Also, with summoned creatures, while your summoned creature are fighting with your enemy, you can flee to rest, repair armor or read books.
Class: Chukonu
Best Race: Argonian, Bosmer, Dunmer or Khajiit
Best Birthsign: Any that you want
Specialization: Stealth
Attributes: Agility, Endurance
Major Skills:
1. Marksman
2. Heavy Armor
3. Hand-to-Hand
4. Destruction
5. Athletics
6. Acrobatics
7. Security
Description: The chukonu is an archer who use bows and elements to attack. They use heavy arming to defend themselves.
Combat Purposes: The chukonu don't have much combat purposes. But, they use heavy armor instead of light armor, unlike most stealth-based classes. Also, they use hand-to-hand to attack (when magicka ends and all bows end also, they must have another mean to attack).
Magic Purposes: No much. The chukonu has Destruction spells to help them: Ranged spells to help along with ranged Marksman attacks; Damage and drain spells to reduce enemy's attributes (including Strength who will reduce the enemy's Encumbrance); Weakness to elements, to help them along with Fire, Frost and Shock spells; Disintegrate spells who will break the enemy's armor to reduce their protection against Marksman and Hand-to-Hand attacks.
Stealth Purposes: The chukonu is a stealth-based character. They have a few of Stealth skills as Major skills to help them against enemy and traps (Marksman and Security respectively). Athletics and Acrobatics will help them in travels, and to flee from too-strong enemies.
Other Skills: If you can train other stealth skills, you will get a more stealth-based character.
Usefull Factions: Thieves Guild
Roleplay Restrictions: The chukonu seems to be a mix of Combat and Stealth character, with one Magic power. I chose Stealth as the specialization because in real life, chukonus are stealth warriors. The chukonu however can be a great mix of Stealth and Combat character.
Class: Daimyo
Best Race: All except Bosmer and Khajiit
Best Birthsign: Any that you want
Specialization: Combat
Attributes: Strength, Intelligence
Major Skills:
1. Blade
2. Blunt
3. Light Armor
4. Destruction
5. Restoration
6. Conjuration
7. Block
Description: The daimyo is a powerful warrior blessed with the ability to cast spells like great mages. They use light armor and heavy weapons to kill the enemy.
Combat Purposes: Daimyo has all ways of hurt the enemy (except the use of Hand-to-Hand and Marksman weapons). With Block, they can block any weapon attack that the enemy will do. Blade and Blunt will give the Daimyo the chance to use all type of weapons (except Marksman).
Magic Purposes: Daimyo has destruction, restoration and conjuration spells to help them against any type of enemy. With destruction, they can damage the enemy, with restoration, they can restore themselves, and with conjuration, they can have creatures as help with the enemies.
Stealth Purposes: No stealth purposes apart from using Light Armor instead of Heavy Armor.
Other Skills: If you can train Armorer and Hand-to-hand, you will get more combat options.
Usefull Factions: Fighters Guild.
Roleplay Restrictions: The daimyo is a combat version of Battlemage. Battlemages are a mix of Combat and Magic classes, but they are Magic-specialized. The Daimyo is combat-specialized.