Suggestions
Sorry to be harsh, but this fruit was not ripe.
Your storyline does not include any interesting details and tells us nothing about Arthur other than that he wore armor and fought with a sword and spear. Also, I found it interesting that Merlin ended up looking like Eric Cartman. I don't know jack about how to do animation, but this animation could use some work especially in regards to movement. Your sound track does not match Arthur at all. That music would work well if it was a gay joke about Arthur and the Round Table knights in the tradition of Tankmen and 300 Queers.