Complex sentence: Fuu's is Windam (Windom in the official English release of the manga), a great four-winged bird; and Hikaru's is Rayearth (Lexus in the OVA series), a wolf with a mane of fire.
Split into simpler sentences: Fuu's is Windam (Windom in the official English release of the manga), a great four-winged bird. Finally, Hikaru's is Rayearth (Lexus in the OVA series), a wolf with a mane of fire.