The resistance band back pedal is a good exercise for strengthening your legs and glutes. This is a great cardio exercise for endurance. It is also great for improving mobility, balance, and knee strength and health. Learn more about properly executing this exercise with the video above.
Regression
To make slams easier, have your client move closer to their anchor to reduce tension on the Beast ropes. You can also reduce tension by using a lighter resistance of Son of the Beast. Another option is slowing the tempo of the slams down or resting 1 or 2 second between each slam.
Progression
Increase the intensity of the slams by having your client move further away from their anchor, placing more tension on the Beast ropes, causing them to have to work harder.