Reading the scroll, Kagara speaks his idea's.
Well this seems simple. Make the handseal and as you do channel the Raiton chakra into your desired hand. As you do, extend your hand and release the lightning, but maintain control over it, forming it into a wall of lightning in front of you. This technique sounds linear, but i believe its not just used in front of you. I think you can block attacks from above with it, and even attacks from below if you jump first to create some distance and make the wall as a barrier between yourself and the ground. Flaw is it leaves your back and sides exposed, offering no defense.
Similar to the above, but slightly better as it protects your sides as well as your front of back. Also handsealess, which helps. As you expell the raiton from you body, form it into a half dome to block in coming attacks. As it creates a half dome, it can protect you far better, and the dome can be formed to protect you from the front and sides, top and sides, back and sides, or even below if , once again you create some distance. As such, a stronger defensive technique, but as this can also be launched forwards after blocking, which makes it a good combo block and strike technique