A Sibling's Oath

Rebirth is as much a curse as it is a blessing. And there would be somethings he wished he'd never known.

As Master of Death, Harry James Potter has learned that better than anyone even if he's only lived two complete lives.

Moving on to his third life, weary and hopeful, he finds himself born as another 'Harry', to be precise Hyacinth 'Harrison' Lukas Evans, the stillborn twin of one Lily Joanne Evans and younger brother of one Petunia Evans.

Unfortunately for Lily, the girl who in another life was once his mother, he isn't the naive little boy obsessed with the idea of his parents and he doesn't find her much to his liking much like his once father.

Fortunately for Petunia however, the girl who in another life would be his tormentor, he takes his role as a sibling with great importance. With no small amount of amusement he decides that maybe things should go a bit differently.

What kind of impact would it have on the future, if his once mother's twin wasn't stillborn, and their older sister had magic? Likewise what exactly is he hiding besides his position as the Master of Death?

*Warning: This is a BL story, the determined pair is Regulas Black x Harry Potter*

**I do not own Harry Potter or any characters really I only own the plot of this story**