Simple as that; Eternal Mangekeyo. An ability to steal the eyes of another Uchiha so that blindness doesn't effect you. Perhaps only temporary stealing (where they would have their sharingan back after a cooldown, though you keep eternal), or perhaps permanent (obviously very hard to accomplish the latter if that is done). If Amat is nerfed and Tsuk isn't too powerful, then this would be wonderful. My friend (perhaps jokingly) offered me their Sharingan, as though Eternal was in. So I thought to suggest this.