Mahoutsukai Syd & Lid

From Storm in Heaven:

Magicians, people with magical powers that have caused their kind to be hated and feared throughout the centuries. This manga contains their tales -- of magic for both good and evil, the struggle to fit into society, and a dark past that haunts them both.

The series includes:

1) Romanesque Variee 2) Mystic Variee 3) Classical Variee 4) Sweet Variee 5) Silouette Variee 6) Crescent Variee 7) Secret Variee 8) Fantastic Variee 9) Nostalgic Variee