Ashura+Indra= hagoromoo's chakra.
Sasuke is not gifted with strong physical energy like Nagato.
You already pointed out that both sharingan and rinnegan has special chakra.
Now what type of chakra do both of these eyes have?
A sharingan's special chakra is a Uchiha chakra.
Now what type of special chakra does the Rinnegan have?
What did this physical energy/Ashura do to the eyes to change its property into a different special chakra?
What is this new special chakra called?
The Rinnegan has a chakra.
It was the chakra of the Rinnegan that enabled him to use its power.
His physical energy allowed his body to handle its power.
Special chakra....Don't know what it call. The 2nd hokage called special chakra. if you use anime logic, we would call the "special chakra" "sacred energy" as in advanced level of spiritual energy! Makes sense right?
I'm not talking about
awaking the rinnegan. I'm talking about
using the rinnegan.
it take the special chakra or spiritual energy to use sharingan. Kakashi do not have the special chakra. So the sharingan depend on his spiritual energy.
It take special chakra or spiritual energy +
physical energy to use the rinnegan to it full power.
Nagato have large life force(physical energy). He could use the rinnegan better than Obito. But he would've been a lotttttt better with the rinnegan if he also had the same quality spiritual energy or the special chakra that the Uchiha clan only have.
Do you understand?
Sasuke do not have godly physical energy to use for his rinnegan. Because of that, he have to deal with a lot of "cool down" moments.
This is where Kishi F-ed up. He never explain how chakra works! In part one, he went on about spiritual energy and physical energy. How you gotta mold them both together to create chakra. Then part two, everything is just chakra.
He had yet to explain what is so great about spiritual energy and all.
bleach, yu yu hakusho and hunter x hunter explains these kind of things very well.