Now that I look at it, I can understand the beauty (and simplicity) of boardchangers. It wouldn't be anywhere near as fluid or strong as the video, but I can see where Raphael, normally useless, could play a huge role in a Hero team. Just slap him and a heartbreaker of the corresponding type on the team and just blast away the boss.
..now if only I had a raphael. Never thought I'd ever say that. (But I have pretty much everything else that would be needed-- Pandora, Vampire, DMeta, and anyone else that could deal a large amount of dark damage.)