Here's one of the more interesting boss fights in Karazhan, or at least as far as the mechanics go with keeping everyone on their toes. After a grueling set of trash mob clearing, you arrive here at the Shade of Aran, who is considered the main "gateway" boss to the latter half of the instance due to the raid being able to teleport to his room once he's dead.
I've taken some cleaner kill videos of him, but decided I liked this one more, as it was an almost complete wipe with a close call finish. Much more exciting! ;)