The Song of the Angels Echoes in the Sky Sora no otoshimono : Season 2 Episode 8

Ikaros arrives to assist Nymph against Chaos. Daedalus reveals to Sugata that she is the creator of the First generation Angeloids which include Ikaros, Nymph, and Astraea. The time has come for Astraea to make a choice: will she do the Sky Master's bidding and destroy Ikaros and Nymph once and for all, or will she listen to Tomoki and find the strength to choose her own destiny? Astraea chooses the latter, and fights Chaos using her Aegis shield and sword, but Chaos is still able to get the upper hand. Ikaros arrives and fights Chaos, eventually plunging her to the depths of the sea so that she passes out.