" In this dark, under this moon, they shall fulfill their contract."
Allways cheerful but when met in a fighting situation, becomes deadly serious. Takes good care for his pet bird(swallow) and interact well with animals. It is pretty hard, if not imposible to make him mad but if you have, run for your life. Also he utters "In this darkness, under this moon, they shall protect their contract." when he kills or do something supernatural.
Rondine always uses a black sword which is Curothuki, meaning dark moon and a white sword which is Shiroyami meaning white darkness. He can change the black sword into a black canon by shouting "Ragnarock" and the white sword into a white sythe by shouting "Apocaliptose". Also Curothuki posess the power to use the blue flames while Shiroyami posess the power to use the red flames. Rondine prefers to use Curothuki which is a more defensive power while Shiroyami is a more offensive power. Because Rondine is not from any universe either gods created, he can't manipulate any matter that's from either world but he posesses the power to manipulate everything that's not from either world which is dark matter. By using dark matter, he can cut through the space from a certain space to another and teleport.
Rondine is the contract that was made between the it and God. He is not a incarnation of anything but just a identity of the contract fitting into God's world to make it go back. He doesn't have any history other then that.