I know this looks like anime but he looks like this overall, just imagine your own preferred version in reality. 

I will decide and write at the bottom of the next chapter.

Ah, I see. Not yet, I have some in mind but since I don't like romance without depth I will try to write a meaningful romance when it comes down to it, for that the LI needs to be involved in the plot majorly. I guess we will find out. :))

LI? What do you mean?

MC:

Bye

What kinda stories have you read?! Ninjas on flying swords in naruto?! LOL, I am curious to see if there is a story like that actually, should be funny. As for Backlash, it is not really. Think about it, a backlash occurs when there is an imbalance. The system cultivates both body and spirit energy at the same time, which means both are growing at the same time, if one grows while the other does not there would be a backlash. As it goes, MC has strong spirit energy and a strong body to contain it. Both combining in balance giving him more chakra.

The system increases his internal energy, not by Senjutsu but by increasing his spirit energy and body power. Chakra is a combination of both. Who said cultivating by using the chakra of nature?