Well besides the obvious reasons, I wish to unlock the third tomoe to advance my abilities and become even stronger as an Uchiha. I also believe the benefits that having the third stage of the sharingan unlocked can greatly help me in the midst of battle. The capabilities that come with having the 3T unlocked can turn the tide of a battle if used by a knowledgeable Uchiha with the abilities to track higher speeds and react quicker to an opponent on the offensive. I am also a fan of genjutsu, and unlocking the 3T will open the path for me to learn genjutsu capable only by those who are sharingan wielders.