Major style revolutions

Sometimes series run for number of volumes and artists style begun to change. Only when you compare first and last chapters you can see the big gap.

Underneath are some examples which I chose. I think Oh!Great made a big leap forward

Slam dunk (vol 1) and late Vagabond (around vol.28) - Inoue Takehiko

Tenjou tenge vol 1 and vol 19 (I think) - Oh! Great

X vol 1 and vol 19 - Clamp