Lord Thorval

Lord Thorval is a human death knight trainer at Acherus: The Ebon Hold in the Eastern Plaguelands, and is particularly teaching Blood abilities to the adepts. After he became a death knight, he wrote a book about his past. He describes his former life, being a paladin and having a wife and two daughters. They died when his home village was burned by the Scarlet Crusade in fear of an infection. During a battle against the Scourge he, filled with hate, pain and disillusionment, swore allegiance to the Lich King and was reborn as a death knight. Despite his oath of allegiance he defected from the Lich King following the Battle for Light's Hope Chapel and now aids the Knights of the Ebon Blade.

Quotes
The blood is life... And as easily as the ebb and flow of blood is controlled, so too is the life of our enemies.
 * Death knight gossip

I have nothing to teach you,.
 * Non-death knight gossip

Lecture
"As disciples of blood, you strive to master the very lifeforce of your enemies. Be it by blade or incantation, blood feeds our attacks and weakens our foes. True masters learn to make blood serve just their strength in battle. Stripping energy from our foes, both fighting and fallen, allows us to persevere where lesser beings fall exhausted. And every foe that falls, energy sapped and stolen, only furthers our assault. As masters of blood, we know battle without end... We know hunger never to be quenched... We know power never to be overcome... As masters of blood, we are masters of life and death itself. Against us, even hope falls drained and lifeless."

Patch 7.0.3 Frost
In Patch 7.0.3, the Frost spec was changed to pure one-handed dual wielding. All death knights were mailed two Frost-Etched Runeblades by Thorval.

Trivia

 * After the defection of the Ebon Blade, the Host of Suffering chose its next Blood death knight trainer in the person of Baelok.