Why does the Voltaire want Renesmee dead and what are her powers?

In the Twilight series, the Volturi want Renesmee dead because they believe she poses a threat to the secrecy of vampires' existence due to her rapid growth and unique abilities as a half-human, half-vampire hybrid. Renesmee's powers include the ability to communicate through touch, show people her thoughts and memories by touching them, and project a sense of love and adoration towards her from those around her.