Eons ago Rai's Brother coerced Edian into finding and submitting Blood Stone, assuring her that it is all for Raizel to be freed from the duty of The Noblesse. The consequence of this act by Edian was a terrible civil war in Lukedonia. Utterly dismayed and not knowing what to do with the horrific result due to her inadvertent action, Edian retreated to her mansion and remain secluded for a very long time.
Centuries passed, and Lagus Tradio paid a visit to her. Lagus deduced that Edian was not coming out of her mansion because she has something bad to hide from Raizel. Lagus then revealed to Edian the real reason she is not coming out, shocking her (who thought Lagus didn't know because she told no one). Lagus, at this point began to manipulate Edian: first assuring Edian (who still blames herself) that what happened in Lukedonia due to her action was all for Raizel, a man she loved, to be freed. Then he assured her that the resulting consequence was tragic but unintended. Finally, Lagus offered her a 'medicine' that would supposedly ease her mind. Edian, obviously not in a right state of mind, took it.
The 'medicine', it turns out, was a drug that turns its user into a puppet for Lagus partly obeying Lagus' will. Lagus, anticipating that stripping his victim's will totally would be found out by others, allowed a minimal conscience of his victim to exist. From then on Edian, by her confession, began to look at the world as if she is 'in a constant state of dream'. Also Edian's body, little by little, started to move not by her will, but by the will of Lagus Tradio (which explains why she acted in such a schizophrenic manner during her invasion of Lukedonia). Slowly but surely Edian was becoming Lagus' tool for treachery.
Lagus' intention was that once Raizel is dead and he conquers Lukedonia, he would then strip Edian of her free will completely, making her his absolute puppet.
Back to present, Rai and others are shocked after hearing the truth. Lagus launches an attack on Rai but it fails as enraged Rai goes all out. Rai shows his anger for the first time and Lagus is shocked that Rai can still summon such power as he continues to receive one major injury after the another. A panicked Lagus summons his strongest blood-red vine attack and launch it on Rai and Edian. Rai with great effort overpowers the attack and counterattack with his strongest attack: the Blood Phoenix, which destroys Lagus. As Lagus's body begins to disintegrate, he laments that his ambition has come to a hollow end, and even with his new power granted by Blood Stone he still could not surpass the Noblesse. Remorseless to the end, Lagus curses at Raizel and Nobles for not making good use of their innate powers to rule the world. With his last dying breath, Lagus warns that by isolating themselves from rest of the world Nobles will be left behind and one day become extinct. With this defiant warning Lagus enters into eternal sleep.
Frankenstein arrives on the scene remembers how he used to tease Edian in front of his Master. In the present, Edian's body is gradually disintegrating. She gently strokes Rai's face and finds him crying. Edian tells Rai that she isn't worthy of his tears and thanks him before biding the final farewell.
Rai apologizes to Edian as she peacefully enters her eternal sleep in the arms of the man she loved the most.
(Check Noble Talk for All which is a celebration by authors for reaching Chapter 400)