Hiccup didn't understand the importance of Charles being gone, but he certainly understood the expression and anger. It was not unlike a feral animal, broken and lashing out at anyone because it could not bear to be hurt again. Before he could even say anything, he felt that same sensation and realized it was the other man who had caused the blast.
It was terrifying to see that kind of power coming from someone in so much pain. He was thrown back against the house and metal bits had been thrown at him as well. He cried out in pain as a dozen or so gashes formed against his exposed skin, which was primarily his face, neck and arms. A few smaller pieces of metal embedded themselves in his skin and blood welled in every cut and abrasion. His metal foot had also broken nearly in half and it had twisted around, causing massive irritation and pain where it had been strapped into place on his calf.
It hurt like hell but Hiccup still tried to lurch forward. He fell on his hands and knees and whimpered a bit in pain. There was no way that it would stop him though as he tried to make his way closer to Nina's father. "Please, I-" He wasn't sure exactly what to say or even what he was asking for. He just hated that they had been affected by the dome's latest pain. "Maybe she will be back."