In what episode does Kaworu appear?

Kaworu is first seen in episode 24, sitting on a stone amongst wreckage due to the previous battle with Armisael, the Sixteenth Angel.

Who is Kaworu in love with?

In the comic parody Petit Eva, Kaworu openly states his desire to marry Shinji, and in Shiinji Ikari Raising Project, Kaworu is one of Shinji’s seven romantic options, and one of three in Girlfriend of Steel 2.