There are other planeswalkers around. Possible in-story link or meta with MTG, but okay
Then the Karate guy that refused a cheatdestroys a small army, a gardner killer and plans to take on a dragon right after being shield bashed five times and fighting an extremely strong knight. Starts to break my suspension of disbelief, but maybe they cheat the goddess gave him is immediate regeneration or similar without telling him?
But then we have the world-building.
A princess without manners that goes around with only one guard, a c(o)unt that can openly mock her without reprisal, the king that does nothing, a sub-human? that has to respect a human merchant but that can again, mouth off the princess in front of the king and in the middle of the road.
Not to say about the sudden "gardner killer" .
Nada, that world, or at last that nation, makes absolutely no sense. It simply can not exist, there is no hierarchy, no respect of ranks or laws, there is open racism but the princess is half-elf and sometimes loved....it is a mix of ideas and concepts without any attempt to make it logical or realistic