If you're looking for manga similar to Blade of the Phantom Master, you might like these titles.
Sugamu Naito is just your average schoolboy. However, his life was changed when he was dragged into a battle between magicians called Makai Jutsushi. Naito was saved by a Makai Juutsushi girl, Yoruyomiru. His meeting with her shook his lost memories. Now that he knows the existence of dark world, he was moved by something that was inside of him, and took a step into battle...
Focuses around two women, Tania and Sasnia, the daughters of Targst Badam. While venturing in a strange, magic-ridden city, they crossed paths with Prince Fante of Sandallos, who was being pursued by agents of the evil king. When they come to his aid, they become targets of the evil king’s men as well. Hopelessly outnumbered, their only hope rests in a magical “dragon seal” which they carry, which allows Prince Fante to assume the protection of a set of magical dragon armor.