If I did it correctly, then this link is to the death from above attempt 28. You have almost 1.5s inbetween when he lands and when you charge. You only get one GCD ability off (Shield Slam) inside the window. Make sure you are back in there ASAP. That and pressing Shield Slam, Dragon Roar and Stormbolt are all you have to do. If he lands at 0s then I believe it should look like: Shield Slam at 0.5s, Stormbolt at 3.0s and Dragon Roar at 4.5s.