Height: 159 cm
Weight: 48 kg
Species: Angeloid
Sizes: 91-56-86
Introduced as the "Delta Angeloid: Close Combat Type".

She is something of an airhead and has limited intelligence, due to having low processing power to be able to have high combat abilities and emotions. She weighs 48 kilograms, stands at 159cm, and her wing type is stated to be "Not Variable" and "Super Acceleration". She is sent by Synapse to dispose of Tomoki after he violates one of their rules.
However, when she is ordered to eliminate Nymph, she breaks off her chain and betrays Synapse, engaging in combat with Chaos.
Astraea has been described as having greater battle capabilities than Ikaros, and possesses two equipments: the super-oscillating photon blade 'Chrysaor', and a shield said to surpass the defensive power of Ikaros' 'Aegis', 'Aegis L'. However, unlike 'Aegis', 'Aegis L' is unable to cover every angle possible, only being able to block certain directions at a time, and it covers about half the area of 'Aegis' in terms of angles. Astraea's weak point is that she was made entirely for close-combat, and thus is extremely disadvantaged against opponents with long-range weapons or attacks, as she has no ranged attacks whatsoever.