DA2 didn't truly jump the shark for me until at certain battle at almost at the very end...
I had decided to side with the mages. We were all holed up defending against a templar attack. Except for once in this game the enemies weren't spawning out of nowhere. There was a single narrow passageway they were all trying to storm in through, so for once I was able to use actually tactics. Naturally I had my tanks lined up in front to keep them at bay with my supporting characters and the few NPC friendly mages who were around raining death on the enemies. They couldn't gain an inch of ground. It was total one-sided slaughter, and I was the one doing the slaughtering. Probably the most one-sided fight I ever experienced in the whole game.
Suddenly as cutscene triggers and the head mage guy (forget his name) is all freaking out, saying we could never win (are you kidding me?). Naturally he decides to use blood magic (because apparently the templars were right: all mages are blood mages), turns into a big demon thing, loses control, and proceeds to attack friendly units because he wasn't anywhere near the enemies when he did this. Seriously, I don't think he made even a single attack on an enemy unit.
Obviously this was all scripted and whoever wrote the script was expecting the situation to feel more desperate, I guess. I think he was supposed to at least kill a few templars before losing control and attacking friendlies. Maybe in the process somehow justifying this guy's decision to use blood magic. But with the way it played out for me, we were kicking ass better then we've ever kicked it before when this guy suddenly decides to use blood magic for no reason, fails to do even the slightest bit of damage to the enemies in the process, and destroys the formation that was working so well. I had to facepalm.