Ruina is an organization of extradimensional beings brought into the world when the Crossgate was opened, lead by Perfectio. Their sole purpose is to gather Negative waves (Negative emotions) to accelerate the awakening of the "King of Ruin"
(VA: Ryouta Takeuchi) The Ruina General of Fire, Pilots the Impetus; a machine that can produce flames, he's usually the one who often Goads the heroes into attacking. In SRW Destiny, he's the one who killed Dr. Kabuto. He has a massive breakdown in 2nd Original Generations when Glacies joins the heroes. He embodies anger and rage.
(VA: Masaya Takatsuka) The Ruina General of Sky, Pilots the Fortes Arla. He embodies pride and is belligerant. Around his death, he fights because it makes him feel as if he was alive.
(VA: Hiroko Uchida) The Ruina General of Darkness, Pilots the Priscus Nox. She has a more active role in 2nd Original Generations as she's acts as the leader of the group until Perfectio is awakened. She also acted as the final sacrifice needed to bring Perfectio into the heroes' world.
(VA: Bin Shimada) The Ruina General of Disease, Pilots the Violaceum. His role was that of weapons production. He created the Skullplume series of machines.
(VA: Yuka Komatsu) The Ruina General of Ice, Pilots the Fabularis, a machine capable of generating Ice. In Joshua's Route in SRW D, you have the option to recruit her. In 2nd Original Generations, she will join after a certain stage. Upon interacting with the Sympathia system, she establishes a mental link with Joshua and they trade memories, "infecting" her with humanity. She along with Ventus are cast aside and considered useless afterwards.
She has 3 years left to live after the war due to her being Ruina if the player recruits her in D. Timespan still stays the same in 2nd Original Generations due to her physical composition. Rim, Joshua, and Gilliam try to find a way to lengthen her lifespan afterwards
(VA: Kenji Nojima) The Ruina General of Wind, Pilots the Studium, a machine that can transform between humanoid and wyvern forms. He was the first Melior Esse before the others. He is considered a Connect Device for the King of Ruin, to study humans and convert negative energy into a useable form to aid Perfectio's awakening, he can even project negative energy outwards as well as extracting it. In Rim's Route in SRW D, you have the option to recruit him. In 2nd Original Generations he joins automatically like Glacies does. When Ventus is exposed to the Sympathia system, he establishes a mental link with Rim, and like Glacies, trades memories. He along with Glacies are discarded.
In 2nd Original Generations, he will be the one to seal the Crossgate. Rim, Joshua, Glacies, and Gilliam seek a way to undo the seal to free Ventus without disturbing Perfectio.