Majuu Senshi Luna Varga

A war erupts as the Dunbas Empire attempts to take over the peaceful nation of Rimbell. Three princesses take up the cause to defend their homeland, with the middle sister, Luna, playing a central role. Known for her tomboyish nature and skill with a sword, Luna experiences a magical event in the castle's cellars that fuses her with the head of a massive green reptile known as Varga, leaving her embedded up to the waist and giving her a reptilian tail even in human form. She must now use her new connection to Varga to fight off a giant invader and save her captured sibling, who has been taken by a pterodactyl.