Alright, some context before I begin:
I've been studying longsword consistently for five months now. This video was taken at the tail end of a 9 hour practice day of very intense drilling and working out (lead by the guy in the yellow). I'm the chap in the blue-and-grey who's fighting -everyone-.
Please view these videos and let me know what I can do to improve, whether it's overall concepts or specific techniques.
YouTube - GSG CAIN fight Pt1.MP4
YouTube - GSG Cain Fight Pt 2.MP4
Looks good, for five months. I haven't been training much longer than you, only 9 months. All I can add is watch your posture and the time of your strikes with the movement of your feet, and add more power and speed. You guys are using the Hanwei feders, which we use as well. They can sting and leave welts, but you can hit a little harder with them than nylon or wooden wasters if you have padding. I applaud your courage for posting the videos. Our group has been meaning to do this as well. All in all good job.
Is the guy in yellow Ben?
Looking good! Certainly better than I was at 5 months. My suggestions would be to focus a bit more on closing the distance, do less stalking, and grapple with the sword.