Yandere Shadowhunters x Natasha

Natasha Fray/Fairchild the older sister of Clary by a year and she and her mom has been keeping a secret from Clary and Jocelyn their mom wanted both of them to forget until they were older and asked the high warlock Magnus but he couldn't take Natasha's something was stopping him from doing it and took only Clary's and so Jocelyn told Natasha she would have to keep this secret from Clary and protect her at all costs and of course she she promised she would do anything for her mother and little sister so her mother and with the help of luke they trained her to fight and protect herself without using runes and she soon become a badass fighter but what happens when Clary turns 18 and they start so experience fighting Demons and being a Shadowhunters and what happens when some people start to fall for Natasha that they would kill anyone to have her.

Warning: I don't own anything and there will be swearing and sexual content