Actually, the Moon Rune represents Compassion and Destruction, not undeath:
Blue Moon Rune
Current Owner: Sierra
Past Owners: Sierra, Blue Moon Village, Neclord
A Rune representing compassion and destruction, this rune also turns its bearer into a vampire. This rune carries with it a huge curse, as it actually dominates its bearer's mind until s/he gains mastery over its powers. When Sierra Mikain came into possession of this rune, she ended up going on a killing rampage, forcing her to retreat into the forest to keep herself from harming others. As she gained mastery over this rune, she was able to tap into the powers of compassion, which diminished her vampiric impulses to drink the blood of the living. This led to the creation of the Blue Moon Village, where Sierra lived with others who had cast their pasts away, such as Rean Penenberg and Neclord. Since then, Sierra removed the Blue Moon Rune from herself and placed it on an altar at the center of the village. However, Neclord, overtaken by the lust for power, stole the Blue Moon Rune and fled, robbing immortality from the villagers other than Sierra. Some of the villagers fled to sustain their immortality through sucking the blood of others.
Although Sierra lost physical possession of the Blue Moon Rune, the rune still recognized her as its master. Thus, when Sierra caught up with Neclord, she was able to command the rune to obey her and deactivate itself.
Neclord used the Blue Moon Rune during the Dunan Unification War to take over Tinto. He unleashed the power of the rune by sacrificing 100 lives to the rune, but the nature of its power is unknown.
fueled by lives, but i dont believe that would make it a representation of undeath, as the Beast Rune, the Rune of Life and Death, and the Rune of Punishment are all true runes that feed on lives or souls. Truth be told, as the Night Rune permits the existence, and the destruction of the Undead, it would more represent undeath than the Moon Rune. It seems more to me that the creation of a vampire was a side-effect of the Rune's destructive tendencies, where as the creations of Zombies does not seem to be connected to the Rune itself, but more to individual vampires.