Love interests who are the sibling of the villain

[pianocello]

I'm making a listing of anime which feature a romantic interest of the main character who also happens to be a sibling of the main or at least an important villain.

The ones I can think of are:
Hyakka Ryouran Samurai Girls
El Hazard
Gundam 08th MS Team


Are there any others? Do you have any favorites of this character type?

[One Vorlon]

Jubei Chan - Jyu's crush is the identical twin of the evil clan leader
Sailor Moon (Doom Tree arc)
X

There are also a couple of messy cases, such as Rahxephon and Tsukihime, where the relationships are . . . complicated.

[Thomas Alan]

Angelic Layer Misaki and Shoko ;)

[Doom86]

Relena from Gundam Wing (yes, Zechs is more of just an antagonist/rival, but should still count)
Tear from Tales of the Abyss

[Garasharp K7]

Erika from Tosho Daimos comes to mind here. She'd have an easier time sorting out her relationship with Kazuya if she wasn't from an alien race trying to conquer the earth, and her brother wasn't leading the charge.
The only other one I can think of would be Linda Plato from Metal Armour Dragonar. Her brother is an ace pilot for the Zeon-like Giganos Lunar Empire. He's basically the Char of the series, though I'm not sure he'd count as a villain as he's mainly just a loyal soldier who doesn't stay in the antagonist role when the real villain of the piece appears.

[William K]

Without getting into too many spoilers, Kurogane no Linebarrels

[mk2000]

Utena

[One Vorlon]

It was more of a love triangle than a straightforward romance, but Escaflowne