Weird Snake - Sirius Black and OC

<<SMUT>>

Eleanore Fox joined Hogwarts half way through the Marauders 6th year and instantly turned Sirius's World upside down.

From the moment he saw her he just found her PLAIN ODD- an enigma he couldn't solve. Nothing about her screamed Slytherin yet there she was- in green and silver.
He found it hard not to think about her to the point these thoughts quickly tuned obsessive and he was constantly watching her!

It didn't help his best friend's infatuation with Evans meant the witch was constantly shoved in his face- Lily had taken her under her wing. This led to increasingly heated arguments between the two- they just couldn't get along.

What will happen when their mutual anger boils over and an ill adviced insult goes too far?

Regarding Lily- the two girls natural friendship was further cemented when a dare led to kiss. This kiss led to an agreement to practice on each other (ready for the guy they would want to date). Their bond strengthened from this platonic intimacy making Eleanore's house inconsequential.

Then there was Eleanore herself- she had no solid memories of her past- just that her mother and father worked for the Ministey as Unmentionables. She homeschooled herself until the day she was 'deemed ready for real schooling' by them at Hogwarts.

Jealousy arises from Sirius's female fan base at his heated interactions with the witch and Slytherins dislike her association with a mudblood.

A violent fight ensues putting Elenore in a coma. Her parents inject her with a mysterious bright blue liquid to wake her up. The number 7 appears on her arm shortly after and a handsome blond boy joins her year whome she gets very close to. Sirius gets jealous but Gabriel (this blond boy) soon reveals to Eleanore he is actually her brother- showing her a branded 6 on his arm. They are the only survivors of an illegal Ministry authorized experiment!- to do what? read to find out...