Fighting a dragon sounds like bad news, but if it's a dragon willing to assume a human form and lord it over some pesky elves and whatnot, maybe it's a relatively weak dragon.
Chris Vs Dragon Lord
Next step is to be asked to rule half the kingdom serving under him in which a fight begins when Chris refuses.
Dragon Lord transforms into a dragon and Chris heroically solos it.
Such is how
The Story of a Low-Rank Soldier Becoming a Monarch