Naruto: I Became an All-Round Ninjutsu Expert After Transmigrating

Hokage transmigration + no System + five chakra natures + human experimentation by Orochimaru, ultimately becoming The King's Avatar of every chakra-nature profession... After transmigrating into the Hokage world as the low-ranking ninja Ling Chuan, he finds that while everyone else frets over having only one chakra nature, he has five from the start: fire, water, earth, lightning, and wind.

Unfortunately, his chakra reserves are pitifully small, and he gets dizzy after using a ninjutsu... Until, through hard work...