Deftones definitely carry a sound that's immediately recognizable as Deftones, although I don't classify nu-metal as being metal, nor do a lot of the folks on this forum.
The Faceless - Planetary Duality
Cynic - Traced In Air
Fell Silent - The Hidden Words
Hacride - Lazarus
Decrepit Birth - Diminishing Between Worlds
Spawn of Possession - Noctambulant
There isn't a female vocalist listed in the credits on the album package itself. Katatonia uses a pretty wise spectrum of effects. That being said, I'm sure it's just Jonas singing through some sort of vocal effects processor or pitch shifter.