Well the MC is a super strong dragon knight so him carrying a big ass sword made sense
To me, it doesn't, because in REal Life you just wouldn't be able to work with such a big sword. Speaking of muscles and so.
However, since this is essentially a Fantasy Universe, anything is possible, im principle.
Edit : Is this one of the reasons why Drakensang didn't sell (apart from the non-existing THQ marketing) : Because one cannot be a "big ass" in the game ?
