Past Arc

Early History
The planet on which the main story occurs was once the domain of angels. However, a D|certain troublemaker went on a rampage for the sake of training, which resulted in the loss of all of the world's angels other than Sariel. Alone, Sariel continued her mission of protecting the planet's primitive lifeforms.

Some time later, a family of dragons appeared on the planet. Sariel was indifferent to their presence, so long as they did not threaten the native creatures. While the dragons wanted to rule the world, Sariel's presence forced them to be docile. Many years later, a young dragon named Güliedistodiez tried to kill Sariel, but instead fell in love.

Vampire Outbreak
Vampires predate the creation of the system. The initial vampires were an unaging species that spread by modifying other's through magecraft and were hunted by dragons. They were considered to be a non-native species by Sariel, and therefore not worthy of protection. They lost the sanity of their previous species when converted, although a Sariel-worshipper named Foddway was the one exception to this rule.

Creation of the System
In ancient times, a human named Potimas Harrifenas learned how to tap into the MA energy of the world in his search for immortality. Potimas' technology quickly spread throughout the world, forcing the dragons to wage war against Sariel and the humans in order to stop the collapse of the world. They were unsuccessful, so instead departed the planet, taking much of the remaining MA energy with them.

With the planet's collapse imminent, Gyurie sought aid from D. D proceeded to create the System, using Sariel as the central energy conduit and information processor. The System forces all the world's souls into a closed reincarnation cycle in which each soul is stripped of its accumulated energy at the end of its life.

Situation After System Activation
The first Demon Lord and Ruler of Pride, Foddway, was a vampire that converted a significant proportion of the world into his kin. After he was killed, the vampires were hunted into extinction.