I feel like they would be siblings who would argue the entire time at the same rank. Also, if this was an animation, I don't think I'd watch anything else.

Looking at this art, it seems to me that they were brother and sister in the story. And then, as a result of the tragedy, he/she dies and Shepard is left alone

⠀⠀⠀⠀⠀⠀⢱⣆⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠈⣿⣷⡀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⢸⣿⣿⣷⣧⠀⠀⠀
⠀⠀⠀⠀⡀⢠⣿⡟⣿⣿⣿⡇⠀⠀
⠀⠀⠀⠀⣳⣼⣿⡏⢸⣿⣿⣿⢀⠀
⠀⠀⠀⣰⣿⣿⡿⠁⢸⣿⣿⡟⣼⡆
⢰⢀⣾⣿⣿⠟⠀⠀⣾⢿⣿⣿⣿⣿
⢸⣿⣿⣿⡏⠀⠀⠀⠃⠸⣿⣿⣿⡿
⢳⣿⣿⣿⠀⠀⠀⠀⠀⠀⢹⣿⡿⡁
⠀⠹⣿⣿⡄⠀⠀⠀⠀⠀⢠⣿⡞⠁
⠀⠀⠈⠛⢿⣄⠀⠀⠀⣠⠞⠋⠀⠀
⠀⠀⠀⠀⠀⠀⠉⠀⠀⠀⠀⠀⠀⠀

great shot

Nice