The Ethereal Writer Redux wrote...
I find that (and by that I mean the cinematic of the RoA) to be just as absurd when Orsino clearly decided to gather up every mage of his for a last stand.
Well, not all of them... there's only a few mages in that sanctum. There's that cutscene beforehand that shows the mages getting mowed down in the main hall. Though come to think of it you have to wonder what their strategy was, putting the individuals most able to aid in the defense of the mages (Hawke and company, Orsino) at the farthest reach of their defenses, and letting the bulk of the mages get slaughtered on the front line...
Besides, it still doesn't make sense for him to do it. It's more understandable for what's going through his mind, but it doesn't make sense for him to do it. He knew people would die. He thinks that turning into a brainless flesh construct that will kill everything in its path is going to solve things?
It was supposed to be an "if I go down I'm taking you all down with me" sort of moment, I suppose. He gave up trying to beat the templars in a way that involved his survival, so he activated the nuke on his forearm and started laughing at Arnold Schwarzenegger, little did he know Arnold was a world class sprinter.