Biblical: Israphel is the Angel of music. It is Israfael's job to blow the trumpet on Judgement Day. He also encourages renewal, resurrection and regeneration. Though all angels sing mighty praises to God, there is a special order consecrated to bringing us the music of the Spheres. Angels speak from the mind and sing from the heart, not as we do through vocal cords.
Evangelion: Israphael is first seen on the Kii peninsula, where it is pretty much just wandering around in the water. Shinji and Asuka are deployed to stop it and Asuka goes at it head on, and splits it in two. It then proceeds to puff up and become two seperate Angels. It is defeated when Shinji and Asuka perform an assault synchronized together based on a song.