Black Rose

The Black Rose (黒キ薔薇) is a legendary phenomenon that is considered dangerous because it once destroyed the Oriana Kingdom, but the true identity of Black Rose is a portal to another world.

Overview
Black Rose is a gate which can connect every world when the two worlds collide until become linked and each exerts influence on each other.

Background
Legend has it that it was used by the Oriana Kingdom, which was on the brink of extinction due to the Velgalta Empire's invasion and wiped out 100,000 soldiers in one night. However, the real story is that the Black Rose are accidently open, which open the gate that connects the demon world and the world where Cid lives and the reason why 100,000 Vegalta soldiers were annihilated was because monsters flowed from the demon world through Black Rose and attacked the Vegalta soldiers. However, even the Oriana Kingdom was unable to control the Black Rose and the monsters also attacked the Oriana Kingdom. But the turmoil ended when a certain someone decided to closed the gate and saved the Oriana Kingdom. Hence, the Cult of Diablos are able to enslave the Oriana Kingdom.

With the Cult stewardship of the "Black Rose" to ensured that the Kingdom would survive in perpetuity, they decide to make a pact with the Kingdom to give the Cult a fair compensation, which is the Royal Blood and the majority of the Kingdom's tax revenue will be given to the Cult, resulting in the Kingdom to heavily invest on the arts was so it could entertain them. Also, the Cult are manipulating the Church to persecuted Dark Knights as a way for the Cult to prevent Oriana from gaining the strength and no manpower to rebel against the Cult, which basically became a puppet kingdom.

Oriana's "Black Rose" Civil War Wedding Incident
TBA

Return to Earth
TBA

Trivia

 * In the Light Novel, Black Rose is referred to as a catastrophe. While in the Web Novel, Black Rose is referred to as a symbol of justice for the Oriana Kingdom.
 * Cid Kagenō tries to make an imitation of Black Rose by releasing his magic into the night sky that looks exactly like Black Rose, when Cid is with the "Vow of Black Rose" troop.
 * In volume 4, it's implied by Mordred that Aurora was the one who stopped and closed the Gate of the "Black Rose" after it slew the 100,000 invading Velgalta Empire soldiers. Hence, the Cult of Diablos was able to enslave the whole Oriana Kingdom as repayment until Raphael Oriana decide to ending the agreement with the Cult.
 * Even though the Cult had the rights on the Black Rose, they were unable to control it as they cannot completely control which demon world that the gate are connects to.