Shortly after regenerating, the Doctor falls into a parallel universe, where Equestria is at war with the Crystal Empire. Falling into the military, the Doctor becomes the Head Tactician for Equestria, alongside Brigadier-General Rainbow Dash, and the Pie Sisters.
This story chronicles the events that happen in this timeline.
The story before this is not required to read before reading this, as it does not directly impact this story.
WARNING: Much creative license has been used.
Takes place in the Sombraverse seen in The Cutie Re-Mark.