He should at least know about bloodbending and some of the other crazy benders out there.
He had the option to go to other worlds and specifically chose this one so for him to be totally clueless about the story wouldn't make sense.
Thanks for the chapter [img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=update][img=recommend][img=recommend][img=recommend]