Also, [@SanaChan] I feel the need to point out- its not that Greatswords were so heavy that most people had to carry it on their back (well, I mean it [i]is[/i] heavy, but its more a strain on your belt and pants than your actual person), it was more the size was unweildy, and depending on how you wore it on your hip, it would either stick way out the back and clock anyone unfortunate enough to be standing behind you when you turn, or the hilt would be too high on your breast and get in the way of your arm. Some of the heaviest two handed swords in use during the renaissance clocked in at about 8 pounds. 

For referrence, a M4 or M16 rifle loaded with a 30 round magazine clocks in at approximately 7.5 pounds. Its definitely not a light weapon, but its not unbearably heavy. 

That being said, I get that this is a fantasy RP, so real world rules and commonalities don't always apply, and its a cool look. Also, yes, this big ole blurb is referencing a singular offhanded comment made in your post. I like talking about weapons. :3