The Heart of Arthas
Matthias Lehner (an anagram of Arthas Menethil) first appears when the player finds a strange object far beneath Icecrown Citadel. Matthias Lehner then shows the player seminal events in the life of Arthas Menethil: the slaughtering of his own soldiers after taking up Frostmourne, the raising of Sindragosa, and the battle between Arthas and Illidan Stormrage.
It is eventually revealed that the strange object is the frozen heart of Arthas, and Matthias Lehner is a manifestation of Arthas' remaining humanity. When this information is presented to Tirion Fordring, he believes the heart can be used to help redeem Arthas and thus defeat the Lich King. Tirion Fordring infiltrates the ceremony where the heart is to be destroyed, along with a cadre of his knights. Unexpectedly, the Lich King arrives at the ceremony and immediately identifies Tirion through his disguise. The Lich King beckons Tirion to stare into the frozen heart. Tiron decides that there is no chance to redeem Arthas, and destroys the heart himself. This process nearly kills Tirion, and drastically weakens the Lich King. Before the Lich King's minions can overwhelm Tirion, the Knights of the Ebon Blade arrive led by Darion Mograine himself. They subdue the Lich King's minions and flee with Tirion before they suffer the Lich King's wrath.
After the destruction of the heart, Arthas' humanity, and thus the spectral Matthias Lehner, are lost forever.
He starts the following quests:
|Naz'anak||First Legion Forward Camp||Sindragosa's Fall||Court of Bones|