I need suggestions

So...we all know that Lina's mom, Sakae, was a Valkyrie (and one of the best), but she was known for being merciless and extremely vicious in the dueling arena (and was bit of a bully to those outside of her her coven (which I'll expand in her parent's profiles), unbeknown to Lina). I need help with a few nicknames for her.

The few that I've came up with are:
Sakae no Akuma (translation: Sakae the Demon)
Oni (translation: demon, devil, ogre or troll... it's a catch all term)
Demon Queen (which was my favorite, but my brother says it doesn't make much sense)

Also, I need a few nickname suggestions for her father as well. Royce, Lina's father, is Sakae's equal in every way. They started dating in their 4th year, which surprised everyone. In their 1st-3rd years, Royce and Sakae were rivals in every way and form. They were equally matched in their academic scores, magical abilities, and were often in Gwydion Manor challenging each other. Even though the two of them couldn't stand each other, they had a mutual respect for each other, which later turned to love. He, too, was part of his coven's dueling club, but he wasn't as serious about dueling as the other members of the team...he was also one of the few outside of the Valkyries that could defeat Sakae.

I couldn't think of any nicknames other than the Demon King, which is why I asked for help.

I welcome to all suggestions.

**Remember, Lina has NEVER seen her mother at her fullest potential, only a few cursing/ threats to a few people (but she had a smile on her face). Lina thinks that her mom is a kind and caring woman, not a vicious and maleficent person, so the nicknames can be as vicious and mean as you like it to be.

Lina also NEVER seen her father at his fullest potential, and also NEVER seen her father harm or threaten anyone...ever.

I not only have your mother's background worked out, but I woke up this morning and figured out your daddy's nik, because . . . that's how I roll.

And going back to who might have known Mommy and Daddy, there is this:

If your mother (and father) are now, in 2011, are 32, they then graduated from SWI in 1997 (1996-97 school year) and started in 1990. So who knew them?

Erywin Sladen: Began teaching Potions in 1992-1993 school year. Both parents would have been 3rd Years.

Jessica Kishna: She graduated the year before they started, but began teaching Transfiguration in 1994-1995 school year. Both parents would have been 5th Years.

Matthias Ellison: He graduated from SWI in 1992, so it's possible he might have known of them if he followed dueling.

Coraline Gallagher: The current school nurse didn't start working here until 2001, but she was a member of Coven Åsgårdsreia and graduated in 1996. That would mean she would have been a 2nd Year when your father started and would have been housed on the same floor every other year.

Madeline Palmescoff: She was a member of Coven Mórrígan and graduated in 1994. She would have been a 4th Year when your parents started.


So there you go. Oh, and some of the elves might know something, too.

Thanks Kerry!!!