Okay, so there are tons of "Mikaelson sister/siblings" fanfics out there.

And I don't really mind them all that much, IF the writer isn't a dumbass whom does no freaking research!

For one thing, naming your Mikaelson sibling. I see tons of people who name their OCs something super modern like Olivia, or Carter or something. LIKE STOP.

Esther and Mikael named their kids 'Niklaus, Elijah, Henrick.' They wouldn't just out of the blue name their daughter Emily or something.

And if you DO want to pick a modern name, make the spelling different and more Scandinavian. Take REBEKAH for instance. So, you could make Emily, Ehmoli or something.

Good names for Mikaelsons are things like; Delphine, Anikah, Ophileah, ect.

Also, your viking character isn't going to be saying things like "Guys, heck, no way, dork."

I know it sounds ridiculous, but you'd be surprised the amount of fanfictions I've come across where the character in the flashbacks talks exactly like we do today, it's annoying and stupid and makes me hate you, so stop.

So, if you're going to make a Mikaelson, please just do your research, read the wiki, do what ever you have to do to make your story believable, it'll be worth it in the long run.