Ikaruga Civil War

The Second War of Ars Magus (第二次魔道大戦), also known as the Ikaruga Civil War (イカルガ内戦), was a war that began when the Ikaruga Federation openly rebelled against the dictatorship and governance of the NOL. It is the first time mankind used Ars Magus against each other.

The war concluded when the Novus Orbis Librarium sent one of its most powerful Knights, Jin Kisaragi to battle, giving him a unit to commandeer. Through Jin's leadership skills and tactics, his unit managed to break down most of Ikaruga's forces. After two days, he managed to personally slay the leader of Ikaruga, Tenjō Amanohokosaka, marking the end of the civil war.

Jin would then earn the title of the Hero of Ikaruga.

According to Jin, there were plenty of others who were capable of ending the war besides him, but nearly all of them were charged with false crimes and disposed by the Wings of Justice. This was done to prolong the war, by eliminating most of those that could have ended it too quickly.

After the war, the NOL imposed a much harsher rule in the world: anyone who rebels against the NOL will automatically be dealt the "Death Sentence".

During the events of Continuum Shift, a flashback in Jin's story mode shows Jin standing right before Tenjō Amanohokosaka's frozen body. Suddenly, he realizes something apparently shocking about the situation, but Terumi appears in his ghost form and devours Jin's memories about the event before taking Tenjō Amanohokosaka's body away and claiming that Jin will make the perfect figurehead hero. This flashback strongly implies that the whole war may have been setup by the NOL or Terumi himself to use Jin, have him win the war and get something in particular from it. After the war, his personality drastically changed into his present cold (with bouts of insanity towards Ragna and Noel) demeanor. Makoto and Tsubaki point out that he had changed for the worst after the war, further reinforcing the idea that the whole war was a sinister plot from the NOL.

The Ikaruga Civil War was started by Sector Seven in order to gather necessary ingredients, namely souls, so that they could create the Black Beast and oppose the Library. That is why Ikaruga is filled with Cauldrons, with all of them set up to gather souls.