You know, now that I think on it more, your theory that Daemon Blackfyre was the brother Bloodraven admired makes a lot of sense. Yes, it could be Daeron (I share Dunk’s frustration about how they’re so similarly named), but with Bittersteel being the “brother I hated” and Shiera Seastar being the “woman I loved,” it makes narrative sense that Daemon — the remaining Great Bastard — be the “brother I loved.” It also fits GRRM’s taste for tragedy.