Some people think that 3T Sharingan is not base mode. I disagree, it's their own power. It's their clan's technique, it's part of who they are. They had to train to get it. It's like saying Haku's ice KG is not part of his base mode.
Actully they dont have to train to get it. They just have to watch a loved on get hurt seriously, and be put in a stressful enough situation, then BAM sharingan. Then once put in more stressful situations, they can unlock more tomoes.
There is literally nothing they need to train to unlock sharingan.
A kkg is a bit different from base mode. And you seem to misunderstand what base mode is.
Base mode is simply the default mode, where the user does not have to activate anything, to power themselves up.
Haku ice kkg is base mode, because haku does not power up anything about himself. He just uses techniques.
This catergory falls into most kkg. KKg like kinimarus fall into this.
Sharingan and byakugan, on the other hand, require the person to activate them. And when activated, they grant the user increased eyesight. They allow the person to react quicker etc.
Techniques like gates, SM, bijuu cloaks, fall into this catergory.
But seriously though. There is literally NO training a uchiha needs to do to unlock sharingan(nor is there really any that can be done effectively, to make a uchiha unlock sharingan.)
It is NOT base mode. The user has to ACTIVATE it to use it.
It is indeed the clans power, and part of who SOME of them were(not all uchiha had sharingan).
It is not borrowed power(with the exception of ems).
I really dont understand why fanboys go through so much trouble to make their character seem stronger and better. I suppose these people have low self esteem, and seek to boost it via boosting a character they like.(not neccesarily saying you are a fanboy op, but I cannot think of a non fanboy who would make a thread about this)