Energy's getting low from doing this every turn, so Kaji is picking his shots. He has moved from one shooting position to a better one, with all the debris now in the way. As soon as he finds any cover, he hunkers down, far enough away to avoid getting hurt by the Earthquake, but he still felt that. Once the last aftershock dissipates, he fires yet another Heavy Shot. You're at your weakest right after you've attacked, right?