What manga is this? ?!

It's about a demon girl - the most powerful one on Earth!. She has wiped out many towns and she was residing in a destroyed [temple!?] when a Hero came, the [fourth one]!. She decides to follow him and have a bit of fun, because he doesn't know that she is the demon!. She falls in love with him eventually and can not bring herself to kill him anymore, no matter how much her [partner!?] tells her too!. Their group of two is joined by two other people, one of which is a [little!?] girl and the other is the hero's best friend!. The demon eventually makes a copy of herself and it tries to take over and defeat the original but she fails at it!. The demon is friends with a dragon and that is the reason why she started to destroy things in the first place, because she was so angry that they "killed" her favorite pet dragon!. The demon has extremely long black hair, is tall, and very pretty!.

Sorry it's all jumbled up and mixed around but if you do happen to know what manga i'm talking about, I would be grateful!.Www@Enter-QA@Com

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