you are the oldest vampire in existence but you are also part witch and part werewolf, your over 2500 years old, Klaus doesn’t know who you are and you let him believe he is the oldest vampire there is. Because of the fact your a werewolf you can have kids you had Isabella but removed the werewolf and witch curse from her, then Isabella had Elena who was adopted by the Gilbert’s so you never met her

you came to mystic falls to find Katherine and stop Klaus knowing others are currently trying to and you have the names of all the vampires in mystic falls, you know Stefan Salvatore is being forced to work for klaus while his brother and Elena try to find Stefan

your walking around mystic falls you look a bit like Katherine so people who know about Katherine may guess your related. In order for Klaus to be able to breed his army he has to find you because vampires will be giving him your name it’ll only be a matter of time before he comes and you can kill him