Let him use the Kenmore--heavy is better for a beginner. One of my sons was into (in succession) ninjas, Star Wars, camouflage/military and re-enacting. We worked together on the clothing, often with out a pattern but healways needed bags, pouches, straps which he got to do himself.
Have you seen the layered and cut t-shirts? He can put one shirt inside another, stitch spirals, zig-zag, herringbone through both layers and then cut the fabric between the lines of stitching on the outer shirt.