On the shores of an Island, a young girl could be seen meditating on a 10 foot tree stump, while standing on leg. She has a serene face while, her skin was tanned as if she was regularly out in the Sun and her muscles were well defined showing that she diligently exercised. Suddenly she opens her eyes and a sense of Joy can be seen on her face.
This young child was none other than Nico Robin. It had been 8 years since she had been born. Although initially confused she managed to figure out that she was being reborn in her mother's womb, and since she had memories of her previous life she started to cultivate her clan's technique in her mother's womb.
The main reason her clan's technique was considered unique was due to the fact it cultivated neutral Qi, unlike other cultivation techniques which gave the Qi an attribute of an element. The main advantage of the neutral Qi was that it could be used to power up an attack or defence technique of any attribute hence theoretically giving the user of neutral Qi an upper hand against other cultivators as they could just use the techniques of elements that countered the element of their opponent. But the main problem was that user had to have absurd comprehension ability as one had to understand the fundamental laws of the element before they could use it to power up techniques, also deeper the understanding of the element more powerful techniques could be used. So often a neutral Qi user would be stuck being jack of all trades as they had to focus on multiple different elements unlike others who devoted their entire time to Master one. The neutral Qi user had to often rely on quick wits and trickery to defeat stronger opponents as they could never match in raw strength.
In her previous life Nico Robin had been an average cultivator but it was the slaughter of her clansmen in front of her eyes that had released all the potential inside her, which helped her cultivate super-fast and similarly improved her comprehension ability to the maximum. She had managed to master 4 basic elements (Fire, Water, Earth and Air) to never before seen limits and cultivate to highest level at a pace 10 times faster than the best genius the world had previously seen.
Even though she was reborn she still had her understanding of the elements but unfortunately for her this world's laws prevented any externalization of the Qi. So for now she could only use the Qi to continuously nourish her body and strengthen her physical abilities.
Although she had only cultivated for 6.5 years she had already reached to her 50% of her previous cultivation realm, this was mainly due to the fact since she already had cultivated these stages before hence she did not face any bottleneck and the Qi in the current world was much thicker and richer than in her previous world.
After finishing her daily round of meditation she soon began her martial arts practice. Since her body had been nurtured with Qi she was extremely fast while not losing out on power either. According to professor Clover she could easily defeat a Lieutenant Commander of the navy and her punches could maybe even hurt a Rear Admiral did not use Armament haki.