Archmage Malin is a human mage located outside the Wizard's Sanctum in the Mage Quarter, in the human city of Stormwind. His original master was Archmage Trelane. Skuerto and Apprentice Kryten are agents of his that he sent to the Arathi Highlands to gather reagents and to recover Archmage Trelane's belongings.
Wrath of the Lich King
Malin's daughter, Emmy - also a mage - was forced into the service of the genocidal blue dragonflight and their insane Aspect Malygos. The Spell-weaver threatened Emmy's family with death unless she served him, and she reluctantly obeyed. She served in Malygos' armies as a captain but did her best to sabotage things on the inside. She was later killed by the Alliance, at the behest of the Kirin Tor.
Upon slaying her, an unsent letter addressed to her father is found on her corpse. The letter is delivered to Commander Saia Azuresteel in Stars' Rest, who sends it on to Malin; sometime afterwards, Malin himself sends the following to the player:
Commander Azuresteel's personal courier saw to it that I received my daughter's letter. The courier also told me that it was you who found it.
I just want to thank you for seeing to it that the letter got to me. I know that times must be tough for all of you brave souls who are daring to fight in Northrend.
Rest assured that I will avenge Emmy. The blue dragonflight will suffer for what they did to my little girl!
With the utmost respect and gratitude,
As the Horde began its mass invasion of Ashenvale in an attempt to conquer Teldrassil and cripple the Alliance presence in Kalimdor, night elf refugees begin fleeing from the World Tree to Stormwind, and Malin was present at the Wizard's Sanctum, holding open portals for the refugees. King Anduin instructed Malin to send a message to Dalaran informing them of the situation and requesting assistance from their magi in order to expedite the evacuation.
Pleased to meet you, <class>.