Phoenix volumes 3-5
Oh, I see. I see now why Phoenix is considered one of the highlights of Tezuka career. The first two volumes were respectively the start and the end of the story, so they were kind of... 'special', spending more pages in setting up everything and finishing it.
It's in these volumes where you can see the real meat of this comic, what Tezuka was planning with the series: a tour de force from ancient times to the future that examines with different time periods and types of stories themes like immortality (literal or metaphorical), the meaning of life, religion, rebirth, and more, all using big leitmotifs like war, love, drama, suspense and mystery.
Because the structure, standalone stories, he can tell a tragic love story in one and a mystery in another, a historical piece about sculptors here and space adventurers meeting aliens there, so there is a nice variety even if the overall theme remains; and as added bonus the different stories sometimes interconnect with each other, making the impression of a sweeping epic tale.
edit : volume 6. Incest with yandere mon?!!