Nanami.
"Nanami is the Hero's adopted sister and a martial artist. Along the journey, she constantly worries about her brother as well as caring for the shattered orphan, Pilika, when she is in her care. During the journey, she questions the war and her and her brother's role in it.
She is horrified of the fact that later on, her brother and his friend Jowy are leading opposing armies and even pleads for them not to fight. She pleads for the hero to run away with her in Tinto (in which the hero can choose to do), but eventually stands by his decision to continue the fight. She is eventually shot with an arrow at Rockaxe Castle while protecting her brother and Jowy when Gorudo ambushes the Hero and Jowy in an attempt to kill them both to seize power."
It's quite heart wrenching to see that happen to such an upbeat and cheerful character. You, Nanami, and Jowy were childhood friends, and you even start the game together as a party. Through a series of events, Jowy ends up leading the opposing army and it absolutely tears Nanami up inside. It's all so sad