Hey man! Thank you very much, I'm really glad you like it! I tried to create a sort of amalgam of the classic Gothic combat mixed with a little Rune, I'm glad it turned out well.
As for the key - I saw someone on the Discord managed to get it, but spoiler alert - it is not in the Arena itself :D
Though I might add an easier way to get it, so people can walk around outside a bit, even if there is nothing, aside from a few little things in the test world.