I would suggest doing a series of smaller thumbnail sketches, maybe 10 or more of both the character and weapon before you move forward with more detailed sketches. These can be very small silhouette to explore shapes. Feng Zhu's video about design process is a good example of this kind of exploration: http://byu.gnomonlibrary.com/training/tutorial/96
Thank you so much for the quick feedback. I will watch and draw smaller sketches.