"I'm well aware who he is." And more than that, he was aware that in some ways their mother had been right about Elijah, for all his claims to morality and nobility he could sometimes be as heartless as the rest of them. When he was roused to be, and it seemed Katerina brought that out in him. He would have to keep that in mind for the future. Whatever the next move ended up being. That would be at the forefront of his mind.
Would he still fight for Elijah? It was a question he hadn't considered but of course she had. He'd hurt Rebekah already, he could see that in that stricken look, the sadness in her eyes. But she had to have known it. He'd never hidden how important his own surrvival was. He was always going to be that way and yet she looked so disappointed in him. He hated disappointed on her. It reminded him once again of their mother and her father. That look. That same look. But when it came to Elijah. Fighting for him.
"Would I fight for him?" he repeated in an attempt to keep her worried as if he were still musing on it. The answer of course was easy in the end. "Always and Forever" he said simply. In the spirit of honesty and all, he was furious at Elijah, and it would probably back and forth between them for a while but of course he'd still fight for his brother, he'd fight for any of his siblings were they here. With the probable exception of Finn.
"That's not to say of course you shouldn't yell at him. Where I can watch. And likely applaud. You can be horrified at the depths of my vindictiveness all you like, I'm used to it, but chastising Elijah for it. I'll want to bear witness." he told her actually laughing at the idea. Rebekah, as he had stated before really could be quite mean. And it never failed to be entertaining to watch her when she really got on a rant.