What's the Name of That Book??? discussion

Hi! I'm currently trying to find the name of a book I read some time ago, but I really can't find the title... I do remember it having day and night "vampires", light monsters who only have powers during the day, and paranormals who only have powers during the night. I think the female protagonist had either day or night powers, but during the end of the book while she is being sacrificed on an island, she is transformed and becomes a hybrid (crossing between the day and night). Oh, and she receives a help from a shifter (bear) in the end who turns out to be her friend/lover... I'm really sorry, thats all i can remember from the series (book). Do hope you could help me out though.

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