Twins. Curses. All of them. You may ask "Huh? But what's so bad about twins?"
It's simple really, there was never a pair of twins in history that weren't evil. In the ages before twins were considered a curse, they were just normal siblings. It was all sunshine and daisies until the Emperor of Xaishiner was accused of stealing a commoners children, A.K.A twins.
A trial was conducted and the Emperor was found guilty. However, he refused to hand over the newborn twins to the mother. The mother was outraged and screeched, "HOW DARE YOU?! THEY ARE MY CHILDREN! BUT YOU CAN GET AWAY WITH THIS SIMPLY BECAUSE YOU ARE THE EMPEROR!! WELL I WON'T LET YOU OFF THIS EASILY!"
She started speaking an unknown language, pointing at the emperor and plucked out some of her hair. She threw the pieces of hair into the air, and shortly after the strands vanished. Those present were shocked and feared for their lives. Her eyes turned black, and blood leaked out of her eyes, dripping onto her light blue dress. The crowd was absolutely horrified at the sight.
Although magic did exist, they've never seen magic like this before! Some of them even burst into tears and hid under their seats. The woman stopped speaking after a few minutes. Instead, she started cackling maniacally and gestured to the Emperor. "You will regret this!" Those were the last words she said before dramatically spinning around and disappearing into smoke.
People looked around bewilderedly searching for the woman. Alas, she was nowhere in sight. They figured she must have used a teleportation spell. Although they were still terrified at war she might have done, they managed to calm themselves down.
Years later, the newborns grew up into a beautiful pair of twin girls. Soft, silky brown hair flowed down to their waists. Sparkly blue eyes shined with innocence. The empire truly adored them. But no one ever would've thought that the girls would soon initiate the mass genocide that would destroy their empire.