He goes to her while the moon is full.

It's delightful to see her skin, softly caressed by the moonlight, when he finally enters her room. After all, it's time! He needs prana for the upcoming war, and he knows she'll be able to provide it. He could, of course, keep killing mongrels, but he wants her and really, hasn't he waited enough?

He knew what Tokiomi Tohsaka had been planning to do with his last command spell (order him to kill himself, the sheer audacity!), so he allowed Kirei Kotomine to kill his Master.

Of course, he had ulterior motives for this.

He had always had every intention to stay, even after the Holy Grail was reached, so he made a new contract, which he had planned to end, task Kiritsugu Emiya helped him to fulfil without knowing.

The girl, Rin, was indeed more interesting than her father... Or Kirei himself. After all, they were really predictable, whilst the girl fought to affirm her claim on which she considered hers, without surrendering, even if she knew the odds were against her. And she was so beautiful, she had developed so perfectly since her fifthteen birthday...

Thus he ended in her room, seeing how her red nightgown had moved with her, revealing way too much of her creamy skin to his red gaze. And he hovered over her for a while, his charisma finally free to it's peek. Then, he kissed her.

His kiss wasn't cast, or innocent. It was demanding, a king taking what was his by right, to which her couldn't help but correspond. She wasn't fully awake yet, but he knew she had been dreaming about him. She must have felt that connection since the beginning too, because he had been the prime, mysterious image in her head while pleasuring herself, for as long as she could remember.

Gilgamesh wasn't sure if her kissing him back and trying to strip him was her thinking the situation was a realistic dream, and wasn't interested in knowing the answer.

He left her lips when her need for oxygen became urgent, only to attack her neck, breaking through that annoying nightgown of hers to reach her breasts.

He had her whimpering in minutes, his expertise showing as he towered over her, already most naked, her covers around them as he slid his hand to her intimacy, his other hand and mouth still teasing her breasts, finding her already starting to get wet.

He liked to hear her moaning, her ebony hair in disarray on her pillow, while her pale skin sported a furious red.

And he kept kissing her, adding his slow caresses to her clit, seeing her arc in pleasure, pressing herself to him in the process.

He released himself from his pants, teasing her with his tip, while she neared her peek. When he felt her come, he slided into her scorching heat, his expertise avoiding making the deal painful for her.

Once Gilgamesh was inside of her, he knew she would be part of his treasure. In his whole existence, nobody had felt as perfect as her.

It was as if the Tohsakas had been honing a perfect mate for they didn't remember meeting. After all, it had been a long time ago, before the vampires had fully become humans. Gilgamesh had saved the then head of the family, and he had sworn his family would produce a good mate for the King of Heroes.

Being inside of her fulfilled the oath, and he enjoyed her nearly into morning, when she finally fainted from exhaustion, her body filled with his seed and her heart with hi soul.

She was his, from the very first second he saw her, and now would always be, thought the first Heroic Spirit when her body was taken in by his Gate of Babylon.

She was his, his most treasured treasure, just second to EA itself, and no mongrel would even put their filthy hands on her.

A/N: I'm taking some liberties here, anatomically speaking, because, well, Gilgamesh is 2/3 god, so he should be able to do things normal humans are unable to, like keep going a whole night, or shooting abnormal amounts of semen. Btw, in this drabble Kirei didn't die, he just had his contract with Gilgamesh broken after the whole Grail thing, and as Gilgamesh went away, Kirei doesn't know he's alive... About the Tohsakas: Gilgamesh met their eeeearly ancestors during his travels. It's not canon, it's just my personal headcanon. RIN IS 18 YEARS OLD!