On his way to met Mikasa, things take a turn for the worst and Eren has to save her from trouble. If anything this was just a rewrite of Eren saving Mikasa, but in the Pokemon world. T for violence.
Eren just wanted a shiny Gengar but no he gets a crazy military dude.
He always wanted to be the very best. No matter what he wants to defeat this man, on the field and off the field.