The Undead Lord is a sinister lord of evil, he commands a small army of Undead. His army is iconically called the Undead Army.
The Undead Lord's Background
All that is thought to be known of the Undead Lord is that he was a Vampire who was loyal to Harkon. He became Harkon's successor's, Valgeir, Champion. Before then, he had found a set of Armor and a Weapon, which he called Valga II, from the Ancient Nordic Ruin of Ruunvald, east to modern-day Shor's Stone. Nothing is known of what happened to him or his Companions.
Note: The armor set and the sword is a reference to the Lich King's armor and weapon.
The Undead Lord's Wrath
Nothing is known of the event known as "The Undead Lord's Wrath."
The Undead Lord is an arrogant, easily angered, and wise person. He believes himself to be unstoppable, and the ultimate force of Evil.
Gods of Worship and Gods of Hatred
The Undead Lord worships Arkay, Akatosh, Nocturnal, Boethiah, Vaermina, Hermaeus Mora, and especially Mehrunes Dagon.
The Undead Lord absolutely hates Mara, Stendarr, Hircine, Kynareth, and ESPECIALLY Meridia.
- He is an obvious reference to WoW's Boss Character "Arthas, the Lich King."