Marwyn

Captain Marwyn was one of Prince Arthas Menethil's captains during the Third War.

Biography
Marwyn was a close friend of Falric, and a confidant of Prince Arthas. Throughout Arthas' campaigns in the Third War, Marwyn was present to help oversee operations and lead the soldiers. When the time came to strike at Mal'Ganis, Marwyn, Falric, Luc Valonforth and Arthas drove into the heart of Northrend and achieved victory, though not without having first attained Frostmourne.

Eventually, Arthas fell to the whispers of the blade. He murdered many of his soldiers, raised them into undeath and turned his two most trusted captains, Falric and Marwyn, into malicious death knights.

Ultimately, Falric and Marwyn accompanied Arthas back to Lordaeron. They stood at Arthas' side as he walked into the throne room and murdered his father. It was Falric and Marwyn who had the task of slaying the citizens of the city, raising them into undeath using their newly gained powers.

World of Warcraft: Wrath of the Lich King
Marwyn, alongside Falric, made his first appearance in World of Warcraft as a boss of the Halls of Reflection, third wing of the Frozen Halls.

Character division
The Captain from Warcraft III was divided into two separate characters, though Falric remains the principal protagonist amongst the two, retaining the most lines and appearances and being the only one playable in-game.

Luc Valonforth was the captain who spoke to the emissary, which is why he appears in a flashback scene, while Falric was the captain unit that was usable during most of the campaign.

Trivia

 * Marwyn's armour appears to share the model of the Death Knight tier 10 armour: Scourgelord Battlegear, although it is much darker and more sinister.