Loki would claim that he hadn't imagined anything like this in a long time, but that would be a lie. When he was alone and lonely, the idea of working by Thor's side had gone through his mind, but he had always pushed the idea aside as something that couldn't happen anymore, considering what had went on between the two of them. Loki had been just as surprised when he was knocked back as well, feeling pain that he shouldn't be feeling. Between he and his bro...Thor, this shouldn't be happening. This creature should be going down without a second thought.
He sat up with a groan, expecting the Hellgod to rain down blows upon him, but it seemed that she had went for Thor first. That had been her mistake. While relieved that she couldn't use the hammer for anything, that didn't mean that she couldn't hurt him, and something that he had thought was long gone (he had tried to kill Thor several times himself, after all), surged through him, letting out a scream of rage.
Forgetting his injuries, forgetting everything that he would normally hold back, he felt a chill going down his spine, watching as a column of ice formed down his arm, coming down to a sharp point that he aimed at the Hellgod as he charged at her, shattering it against her as he managed to knock her off of Thor, likely mostly by surprise, if the flicker of shock he saw cover her face was any indication.
He wasn't done with her yet, though. He still had the Casket of Ancient Winters hidden, calling it to him and thrusting it forward, using it to freeze the Hellgod solid in place. He sent the casket away again, taking a second to force his features back to their Asgardian ways before turning and looking back at Thor. He didn't want to face anyone while looking like that.
He turned to Thor, reaching to help him up off the ground. "Even with the weather, I don't think that will hold her for long." It hadn't held Heimdall forever, and he was pretty sure that she was stronger. "We need to go."