I do not own Fire Emblem.
LIKE A SISTER AND A BROTHER
Words that were as familiar to his ears as his own name sprung from Ewan's lips as the bandit moved towards his sister. With a gesture, the man lit ablaze, and Tethys shouted a thank you over the roar of battle. But she didn't need to...Ewan couldn't ask her to show gratitude for anything, not after all she had done for him.
He was five and she was eleven when their parents died. Despite her own pain, Tethys had consoled him through all hours of the night and day. She gave him their only ragged blanket when it grew cold, and most of the food-she still never had admitted to that, but growling tummies at bedtime didn't lie. And he knew her dream of becoming a herbalist...all thrown away to dance so they could live...so he could have a proper childhood. As soon as she heard that he wanted to be a mage, she took the week's journey to find Saleh to teach him-in the middle of winter! Tethys never complained about it, though. She said that he was her little energetic world and to have him grinning and asking her if she knew how many legs a centipede really had was enough.
So no, it was wrong for her to thank him. Protecting his own beautiful, graceful, slightly over-protective world was the least he could do.