Blue Mage: The Immortal's Handbook by Shikubokubo

Introduction
Whilst leveling Blue Mage I had many, many questions about the job. This guide is a compilation of everything I have learnt whilst leveling Blue Mage. Enjoy!

What is a Blue Mage?
The Blue Mage is a fighter-mage class. Often known as "The Immortal's" they possess the ability to mimic enemy techniques. A Blue Mages sole purpose is to protect the empress of Aht Urghan.

Obtaining the Blue Mage job
To obtain the Blue Mage job you must complete the quest An Empty Vessel.
 * First speak to Waoud at (J-10) in Aht Urghan Whitegate.
 * Ask for a divination and you will be asked a series of questions.
 * There are several different combinations of answers that you can use in order to proceed with the quest, the easiest being to pick the last option for every question.
 * If done correctly Waoud will ask for one of three items.
 * The Dangruf Stone is obtained from a ??? in Dangruf Wadi at (I-5).
 * The Siren's Tear can be found at a ??? in North Gustaberg around (J-8). To obtain the Siren's Tear you must remove all weapons, shields and hand armour.  Failing to do so will make the ??? move to another spot along the river.
 * Valkurm Sunsand can be found at (H-9) on the boat in the Valkurm Dunes.
 * Talk to Waoud after one game day and tell him that you wish to help him.
 * Trade Waoud the requested item and you will be asked to travel to Aydeewa Subterrane.
 * Zone out into Bhaflau Thickets and take the tunnel at (I-7) into Aydeewa Subterrane.
 * Follow the tunnel into a large room and drop off the ledge into a room with several Diremites. Turn left down a steep ledge into another large room filled with leeches and a large pool in the centre,
 * Step into the middle of the pool for a cutscene.
 * Answer yes to both questions.
 * After the cutscene you will be transported back to Aht Urghan Whitegate.
 * You will have received the key item Mark Of Zahak and can now become a Blue Mage.

Subjobs
Blue Mage is a very versatile job and as such there are many useful subjobs. In this section I will discuss the main strengths and weaknesses of the more common and a few of the rarer subjob combinations.

White Mage

 * The White Mage subjob is very common at low levels. The ability to cast Cure at level 1 is extremely useful since a Blue Mage starts off with no spells of their own.
 * At higher levels the boost to a players MND increases the potency of their healing spells such as Wild Carrot and Magic Fruit as well as providing various buffs such as Protect, Shell, Aquaveil and Blink.
 * This subjob however provides no offensive traits.
 * Job Traits
 * Level 20: Magic Defense Up I
 * Level 30: Clear Mind I
 * Level 50: Auto Regen
 * Level 60: Magic Defense Up II
 * Level 70: Clear Mind II
 * Job Abilities
 * Level 30: Divine Seal

Thief

 * This subjob is often used from level 30 onwards because of the ability to stack Sneak Attack with many physical blue magics.
 * After level 60 the ability to use Trick Attack with a powerful blue magic like Frenetic Rip can help a lot with hate control allowing the damage dealers more freedom to do more damage without fear of taking hate.
 * This subjob is also great for farming. The Gilfinder and Treasure Hunter job traits will increase the amount of drops / gil obtained from defeating monsters as well as the ability to Steal items and Mug gil from enemies.
 * Job Traits
 * Level 10: Gilfinder
 * Level 20: Evasion Bonus I
 * Level 30: Treasure Hunter I
 * Level 40: Resist Gravity I
 * Level 60: Evasion Bonus II
 * Job Abilities
 * Level 10: Steal
 * Level 30: Sneak Attack
 * Level 50: Flee
 * Level 60: Trick Attack
 * Level 70: Mug