The Phoenix is an immortal entity that has taken part is multiple stories during the course of human history. This being is shown to have sympathy with many characters in Osamu Tezuka's stories, and often share its seemlingly-illimited powers to help them reach their destinies.
Resembling the fire bird from the mythology of same name, The Phoenix not only is capable of being reborn from flames, but also is capable of healing others and even granting them immortality.
The Phoenix has also shown to have taken part in not just the human history, but also all species' course of evolution, including the humans' and even the earth's rise and downfall multiple times, if not the whole universe's altogheter.