FimFiction Link - Short ID: 215302/all-for-one---one-for-luna
Published: Sep '14 — Jun '15
Somehow, this fic manages to make one of the most natural ships seem contrived.
Twilight's mysterious illness causes her to feel unspeakable agony whenever she is not in a position to absorb starlight or moonlight. Conveniently, Luna can channel moonlight, even during the day, and so they have to maintain line of sight until Twilight is cured. Cue some "handcuffed" shenanigans, since they can't be separated even if Twilight has to use the bathroom or sleep, while hiding that they like each other the whole time.
It's not just the Tuna, the story features a very complicated headcanon for the illness that involves starbeasts (specifically the Ursae), the Tree of Harmony, Tirek's magic and Twilight's magic. The description isn't impossible, but watching Twilight put the pieces for unraveling it never seemed entertaining, just contrived.
Aside from that, the fic is well edited and the characterization of Twilight, Luna, and Celestia was all good. There were a few cute moments.