Not in the same way he was when his sons were taken from him, that was different. There was nothing he could have done to change that situation at the time. He had been in a net, Thor had him and no amount of fighting was going to free him from that in order to save his children. This situation was different. There were things he could do, things he was going to do and he could hopefully help this from becoming tragedy. What had him numb was watching someone very dear from him so... emotionally detached and not in a good way.
Idun was so bubbly and vibrant. Even when she was angry or upset, she still had a brilliance about her. Rather like a polished up bit of amber. Homey, warm, happy and sweet like honey. Loki couldn't recall how Sigyn looked after the incident, after they'd tied him down. He didn't know because he didn't look at her for a good long time. Not only out of his own shame and guilt, but because he knew damn well that seeing her in pain was going to just compound the pain in his heart into something he wouldn't have been able to bear.
He was absolutely no good with emotions. But he adored Idun and to see her brilliance diminished made his chest ache and he'd do anything he could to help her. If only he knew what to do to help her. He was trying, taking the journey he was taking was proof of that. But there was the part of him that was afraid, deeply afraid, of the answer Hel would have for him. If Bragi was in her hall and dead... there would be no consoling his sister. There would be no peace for her and if he loved her as family, as he deeply believed he did, he should be able to help her.
And there was this vision of her doing as Nanna did, immolation by her husband's funeral pyre... he couldn't let that happen. He'd have to find some way to make it better. He wasn't losing someone else. He was done having people he loved taken from his life.
But he didn't know what to feel. Love for his wife, love for his sister, fear for them both. Fear for Bragi. It was too much, too different at one time. He couldn't handle it. Standing in Niflheim was a bit too real for him. Somehow the blood puddle seemed less real. He should have stayed, made sure that Idun was taken somewhere safe, but Sigyn would see to that. He couldn't breathe, he wanted to escape.
At least his sense of urgency was still in tact. Even though he badly wanted to just run away to Lauer and hide among the fir trees, with his head in his hands until he either exploded from emotional overload and his heart actually broke or he figured something out, he wouldn't. That was a bad plan. His mother, if she was still alive, would know the very second he crossed onto her island in Muspell and then he'd have to explain things to her. Because he refused Laufey nothing. But not just that, he needed to actually do something to help Idun.
So when he stepped out of Concept into the wilds of Niflheim it was at a full run. A run that changed as he moved. Loki's body started to hunch over. He'd never be fast enough on two legs and there was no appearing right in Hel's hall. It didn't quite work that way. Hel's hall was mostly off the radar, which is why Odin sent him to find out about Bragi. Each stride he changed a little more, hands into paws, feet into paws, thick shaded fur covering his form... face lengthening. It took no more than a few seconds before he was running on four legs, lupine form at full speed, toward his daughter's hall.
It never occurred to Loki as he crossed the bridge that he'd never, as far as he could recall, have been in a different form in front of his children. He needed but to growl to be allowed passage across the bridge, then ran all the way into her hall, stopping suddenly and unprepared for the slip on the entryway floor he skid across it into a wall. There, exhausted, he gave up. His wolf head looked up at an attendant while he panted -it had been quite a journey for man or beast, gave a warning growl and laid down to relax a bit until he had enough energy to change back. With a deep sigh, he closed his blue eyes for a moment. Hel would be along eventually. Her servants were notoriously slow, but he'd just growled at one and it would give him time to get some energy back.