physical energy and spiritual energy= Chakra, To use Chakra for anything be it, walking on water, tree climbing, genjutsu, ninjutsu, medical ninjutsu, etc, you need "Chakra control", it's part of the foundation.
After Basic Chakra control is more advanced stuff like "Shape Transformation" for jutsus like the "Rasengan" (which requires high chakra control), then add that with, "Nature Transformation" which gives your chakra the element you have a affinity for, be it, water, fire, earth, lightning, wind or even a KG.
So these sound be the basics of skills before you can perform jutsus or techniques. It's all for the realism, if it's logical it should be added.
Follow @SLO_MMORPG