I assume this symbolism was intentional:

• Robin and Sunday are both depicted with the constellation Gemini, the Twins constellation. Very straightforward.
• As for Cyrene and Phainon, their constellations are Pisces and Aries, respectively. Aries is the first sign of the Western zodiac, while Pisces is the last. You could poetically phrase it like this: "It began with Phainon and ended with Cyrene", or "Phainon started it and Cyrene finished".