Can an Uchiha remain powerful without embracing hatred? Tobirama Senju stated that hatred births the Sharingan and strengthens it:



Can an Uchiha remain powerful without hatred? If not, does this imply that Itachi was full of hatred?
I don't think hatred is the only feeling that makes an Uchiha powerful, since many strong feelings (e.g. pain) can strengthen him, and this is just a quicker way to gain more power.
If an Uchiha sees their close friend or relative die, they gain Mangekyou Sharingan, but the feeling of hatred is not a necessity (Itachi hated no one when he saw Shisui commiting suicide).
So, I believe the feeling of hatred CAN make an Uchiha powerful, but it's not the power source. In short, a strong feeling is just a trigger, and once you awaken the Mangekyou Sahringan with it, you remain powerful.