If you're looking for manga similar to Ao no Souyoku: Phantom of Dragon, you might like these titles.
A traveler in search of his father chances upon a pair of twins about to be buried by their village. The villagers claim the two are cursed but he rescues them. He soon finds out what makes the villagers fear them: the siblings have the power of angels and demons. But he has his own secrets as well...
Based on the Valkyria Chronicles video game, it centers on two people. Mintz, an orphan who had lost his family, joins up with the Gallian military. Julius Klose is a sniper with the Gallian army.
Due to a botched binding spell by the royal mage, the kingdom of Bananafry is thrown into chaos and the princes Pierre and Pyoerre are transported to a distant land. With the aid of Sticker, the court alchemist, and Gino, both of whom were also caught up in the effects of the spell, the princes travel through foreign lands in search of a way home.
One day, when Rio attempts to retrieve a cat that wandered into the street, he is hit by a car right in front of his brother's eyes. Everything fades to black. In the darkness, a voice offers a choice: to live or to die. Fading rapidly, Rio gives the obvious answer: to live! Rio awakens in a world filled with foreigners and strange animals he's never seen before. That's not the only odd thing–Rio now has the form of a black cat! He quickly learns cats are revered in this world because of their special role as familiars of wizards.
Kiichi and Kanoko are brother and sister who have just lost their parents. They move to the deep countryside, to the home of their relatives the Toba family. And who is Toba-sama? A hearth-deity who has been watching over the Toba house for 150 years. He uses abusive language and is very ill-disposed, but he's a softie at heart and has a strong protective side. And this deity names Kiichi for his successor! The life of the two siblings is about to change at 180 degrees!
Somewhere between magic, art and science exists a world of alchemy. And into this world travel Edward and Alphonse Elric—two brothers in search of the Philosopher's Stone, the ultimate alchemical treasure!