Visions of Atlantis is a symphonic power metal band from Austria who sound similar to Nightiwsh, though their equal mix of male and female vocals is reminiscent of Lacuna Coil.
Samples:
https://www.youtube.com/watch?v=cdU5Lv4s114
https://www.youtube.com/watch?v=Bi7gZghczT8
They are currently working on their fourth album due later this year, though that seems unlikely. The band has been pretty silent for a while now.