I was on my way to Tennocon in Quebec, dressed as my personal Tenno from the game Warframe. I saw a costume shop with a perfect looking Amp, and stepped inside to buy it, and upon putting it on my arm found myself in Equestria.
Karn, is one of the oldest Tenno to still live. But is betrayed by one of the newer Tenno, Greavus. His ship was damaged during his chase for Greavus, but ended up crash landing on Equestria.