Seimaden

Seimaden is a Shojo series by Higuri You, first published in 1993 and spanning 10 volumes plus a one-chapter prequel. The art style is somewhat remiscient of CLAMP's RG Veda, as both were published by the same company.

It tells the story of Laures, who became a demon to save his wife, Alice. He was tricked and Alice died, and he vowed to live long enough to meet her reincarnation.

Once this finally occurred, things got a little strange. He found her during a war between the demons and a human tribe, the Azel people. He meets Hilda once as a toddler, then leaves her, and the ongoing war, again. When the kings of the Azel and the demons fight each other, they are somehow sucked into their swords. Laures takes the Azel sword with Kaimei's power in it, and the war ends. He seals the demon world off and regularly stalks little Hilda. He sees that she is developing a bond with Roderique, whom he senses bad things will happen to in the future regarding the Azel power.

Realizing that the most logical course of action is obviously to not keep the Azel sword safely in the sealed demon world, Laures responds to this potential threat by exterminating the Azel, wiping Hilda's memory of her past and sealing the Azel sword inside her before sending her off to wander the world. However, Roderique is still alive, and he desperately seeks Hilda and the power of Kaimei. When he finds them both in one go, he is Demonically Possessed, and things go downhill from there.

Around this, there is the typical Melodrama that can be expected, lots of Bishonen and a plot that is often unclear.

Tropes used in Seimaden include:

Abduction Is Love: Averted at first. Laures explicitly brings up that this will make Hilda hate him, so he didn't take her to the demon world and just wiped her memory of the event. She later falls for him anyway.
All Girls Want Bad Boys: And if they look like good boys at first, don't worry, something will come along.
Exclusively Evil: All the main demons. Kaimei, Laures, Zardi, and pretty much everything that lives in the demon realm. The only exception are those who happen to be associated with feathers, Tetius and Iria.
Bastard Boyfriend: Zardi; Laures
Bishonen Line
Blood Knight: Zardi and Laures at times, too.
Bodyguard Crush: Jiji on Count Berk.
Brother-Sister Incest: Karon and Iria greet each other... very... intimately, and Karon's world lost all meaning once she was gone.
But Your Wings Are Beautiful: Laures thinks his demon form is disgusting and worries that Hilda will reject him for it. His demon form looks exactly like his human form, with the addition of little bat wings above his ears. He also has lots of useful superpowers because of it, and Hilda thinks he is cute.
Byronic Hero: Laures fits this trope perfectly.
Casanova: Laures. Slightly crosses over into Serial Romeo when he claims he had feelings for the former priestress of Azel. Either way, Hilda may be the core of his world, he frequently is seen screwing other women even after she returns and he started wooing her.
Cannot Spit It Out: If Laures had decided to approach Hilda and inform her about the Azel powers and explain what might happen in the off-chance that someone steals the Azel sword from him and gets Rod possessed, there wouldn't be much of the original plot left. Because of his creative alternative choice, thousands of innocents died, Rod got possessed exactly as was planned and Hilda is fatally injured so that Karon can manipulate him to try and cause the end of the world. Once Hilda regains her memory on her own, he still refuses to explain anything to her and leaves her in the care of the possessed Rod, despite his initial concerns for what this might end with. Anything better than being honest with your love interest.
Crazy Jealous Guy: Zardi
Dark and Troubled Past: Laures' past life.
Dark Is Evil: Kaimei, Laures, Zardi, all those hordes of ugly demons...
Damsel in Distress: Hilda. Everyone wants Hilda, either for harm or for love. Sherryl also has her moments.
Dude in Distress: Laures gets this a lot.
Draco in Leather Pants: The way the author treats what Laures and Zardi do out of love, or in Zardi's case, unrequited love.
Driven to Suicide: Sherril. She kills herself when Tetius threatens to hold her hostage and exchange her for Hilda, whom he wants to kill. Sherril jumps out of the tower to no longer be a burden to Rod and Hilda.
The Empath: Iria, which goes hand in hand with telepathy here, though it's only there so that Iria can state how deep and true Laures' love is.
Even the Guys Want Him: Laures is hit by this so very much. Tetius, Count Berk, Count Marion all want him due to his beauty and strength.
Fantastic Romance: The primary romance relies on one soul being reincarnated and the other becoming a demon and living long beyond human years.
Fate Worse Than Death: Sherryl
Good Wings, Evil Wings
Green-Eyed Monster: A much easier explanation for how the plot starts is that Laures was simply envious of Rod and acted out of spite.
Half-Human Hybrid: Asbar is the half-demon child of Laures and the priestress of Azel.
Hot-Blooded: Zardi
Huge Guy, Tiny Girl
The Ingenue: Sherril
I Will Protect Her: See, everyone is after Hilda.
The Jailbait Wait: Laures with Hilda, whom he first meets when she is a toddler. He promises to return for her when she's old enough. At this point he already is already as old as to have bastard offspring beyond Hilda's years, and he possible is hundreds of years old. "Old enough" is 15 or 16, by the way.
Lap Pillow: Laures and Hildra, both ways.
Laser-Guided Amnesia: Laures does this to Hilda, which he claims is for her safety.
Leaving You to Find Myself: Rod gains the power of the Azel sword without needing Kaimei, so he needs to leave to get more control over it... leaving Hilda to hook up with Laures, despite having spent most of the series hoping she'd pick him.
Light Is Not Good: Tetius may look like an angel and Karon has all his pretty flowers, but....
Love Before First Sight: Laures to Hilda, again. She not only has Alice's soul and Alice's looks, but also is compelled to love Laures due to Alice, it seems. Also, Zardi later claims that he also fell for Tetius the moment he saw him.
Love Confession: Right after she learns he really is a demon.
Love Dodecahedron: Laures loved Alice, who became Hilda, who is in love with Rod, who also loves her, then Teti is in love with Laures, while Zardi is in love with Tetius.
Love Makes You Evil: Pretty much all of Tetius' evil stems from a desire to see Laures on the throne. Once he gets over his obsessive behavior, he's a pretty decent guy.
Love Hurts
Love Redeems: Realizing that he's developed similar "silly sentiments" towards a human, like Laures to Hilda, and just how horrible he felt when he ignored them and (accidentally) put Sherryl through a fate worse than death made Tetius change his mind about killing Hilda. After ghost Sherryl kissed him goodbye, he never does anything malicious again.
Loving a Shadow: Unintentionally, but especially Laures' love for Hilda comes across as this, and Hilda often doesn't get why she is in love with him.
Manipulative Bastard: Tetius
Masochism Tango: Tetius and Zardi.
Mayfly-December Romance: Laures and Hilda, again.
Melodrama
Morality Pet: Sherryl to Tetius.
Murder the Hypotenuse: Hilda is constantly hit by this, though she is "in the way" because she is making Laures and Roderique soft in the eyes of Tetius, Count Marion and Maruka.
Not Blood Siblings: Laures and Alice grew up as brother and sister, yet don't suffer from the Westermarck Effect.
Opposites Attract: Just what does the kind, compassionate Hilda see in the ruthless Laures? Same for Alice, who claims to know the true him no one else sees, probably because it only exists for her. He treats almost everyone else as crap.
Plucky Girl: Iria
Poor Communication Kills: And HOW. The whole plot hinges on the fact that Laures steadfastly picks every option plus overkill that is not being honest with Hilda. It ends up with him being coaxed into committing country-wide genocide (again), and later used as tool to destroy the world.
Rape Is Love: Zardi to Tetius and back.
Redemption Equals Death: Karon
Red String of Fate
Reincarnation Romance: Here, it means someone has the same soul, perhaps a few feelings, and the same appearance as the prior life. Otherwise, the individual is entirely different in behavior and personality.
Rescue Romance: This pretty much amounts to the reason why Hilda loves Laures; that and he's cute.
Roaring Rampage of Revenge: Jiji, when she sees that the Count is being transformed into an ugly demon by giving his castle to demons.
Romantic Two-Girl Friendship: Hilda and Sherril.
So Beautiful It's a Curse: Both Laures and Hilda attract various creeps due to their beauty.
Stalker with a Crush: Laures to Alice's soul, this reaches a peak when he breaks into the house where Hilda lies ill, and she confronts him about the memory theft and makes it very clear that she loathes him. His response? Pin her to the bed and ignore her cries that he's hurting her while angsting about why Alice just won't appear despite Hilda looking like her.
Stalking Is Love: Throughout the manga, Laures is depicted as tragic and devoted, Hilda just gets over all the things he puts her through and they end up together.
Star-Crossed Lovers: The air of the human world is poisonous to demons, and likewise that of the demon world is poisonous to humans. Cue angst.
The Starscream: Tetius planned to betray Zardi all along and was never loyal to him. Zardi was only a tool to make Laures stronger.
Stockholm Syndrome: Tetius to Zardi.
Tall, Dark and Snarky: Laures
Undying Loyalty: Tetius to Laures.
Unlucky Childhood Friend: Rod to Hilda.
Warrior Prince: Laures
What Do You Mean It's Not Romantic?: Laures and Alice in bed calling up fond memories over the time she threw herself onto his not-metaphorical sword: as in, he threatened to kill her and she agreed, if it meant that she would be no longer an obstacle to him. Also, Laures having a romantic scene with Alice's severed zombie head, which then rots away, kissing the remaining skull, standing on a field where he apparently skinned or burned people down to their bones and declaring love to Hilda. All of this is presented as being very romantic rather disturbing.
White-Haired Pretty Boy: Tetius and Karon.
Wife Husbandry: The premise. Laures decides to live on long enough to meet the reincarnation of Alice.
Winged Humanoid
Yandere: Tetius loves Laures and wishes to kill Hilda so that Laures can reach his true potential. Count Marion is the same in the past.
You Are Worth Hell: Laures' reason for becoming a demon. Granted, it's not much of a difference than before since he already loved making hell on earth. Human world was happy to be rid of him.
You Got Spunk: Gargul to Hilda.
Your Universe or Mine?: Hers, as the closing splash image shows. Laures became human and married Hilda.