Sialater wrote...
By the time the Rivalrymance ending rolls around, Anders is broken. (Now, Ryz, hear me out before you yell at me.)
Hawke has spend the past 6 years telling him that the defining moment in his life, when he helped his friend with the best of intentions, doomed them both to the worst kind of existence. Neither Anders nor Justice ever even dreamed this would happen. They went into this symbiotic relationship, each thinking that they'd be different. The worst couldn't possibly happen to them.
They were wrong.
Anders' unresolved anger, apparent even in Awakening, is there, simmering under the surface. A year in solitary, pre-Awakening, didn't help. Neither did Anders apparent transfer within the Grey Wardens away from the protection of OUR Warden, and back under a Templar's thumb. Slowly, Justice started to become infected with
Anders' anger to the point where he slaughtered his brothers in arms.
THIS is Anders' first wake-up call that **** ain't right.
He leaves for Kirkwall to either hide or track down Karl or both. And ends up getting angrier when he realizes his old friend and lover is bait in a trap for him, and only by the grace of the Maker and Hawke that he wasn't trapped in it. This is the second time he loses control to Justice.
The third time is that mage girl who's name utterly escapes me. I've never let her die, so I can't say what he does there, but this is clearly warning sign number three. Anders is losing it.
He dials back for a while, whether because he's content with Hawke, or she really is the distraction Justice claims, is unclear since we're not in Anders' head and we're not given a lot to go on. But Justice is quiet for a time. Probably because nearly killing/or killing that mage scared the hell out of Anders and he manages to wrest semi-permanent control back away.
Hawke, on the rivalrymance path, spends almost every moment in game that they're together underscoring how wrong he was. (Unfortunately, you can't do this without bashing mages in general which is stupid.) This judgment by Hawke starts wearing him down and he begins to question everything. This is the point where Hawke starts breaking him.
The Rivalrymance is brutal. There is no sugarcoating it, you're calling out the person you love (as Hawke) on his **** in the most blunt fashion possible. Sometimes, you're downright cruel. Does he deserve this? I don't know. Depends on your view of abominations.
Anders loves Hawke. Any gender, any morality, he loves Hawke. The Rivalrymance may be tough love, but it's borderline abusive. By the time he emotionally blackmails Hawke into helping (or not), he's ready to die. He's not
suicidal, but he's convinced he's no longer deserving of life. Blowing up the Chantry is Justice for the mages because it forces them to fight. They can no longer be passive. As Justice says in Awakening, "Why don't you strike a blow against your oppressors and ensure they cannot do this to anyone else?" If the mages rise up, they can't be unilaterally oppressed any more. (Not my logic -- hell it's not even Anders' logic, this is Justice, remember?) Once at max Rivalry, Anders tries to undo the bomb, but Justice, now corrupted entirely into Vengeance, takes over and prevents him from doing anything. Couple this with the mage underground imploding due to Grace's stupidity and you have an incredibly desperate man and corrupted spirit.
The Chantry goes boom.
Now, the hard part. Anders, by now, is a broken man. He's clearly lost control of Justice/Vengeance, not once, but four separate times, if not more. After all, he's been having blackouts with Justice/Vengeance doing Maker knows what while he's out. He knows he cannot be trusted. He no longer even trusts himself. And Hawke, the one rock he's come to depend on, the one constant in his personal hell, hasn't killed him. In fact, Hawke offers him a chance at redemption, a chance to try to make up for the ultimate crime of becoming an Abomination. Restore
order to the Circle. Annul the blood mages (whom he doesn't agree with anyway). Try to save the City from splintering into lawlessness. His will is gone. All he has left is Hawke. He doesn't even have himself.
Now, the problem with this is a lot of it is dependent upon subtext in a broken game path. I reserve the right to change my analysis if I ever get to actually play the full, unbugged Rivalry path. 
Do I agree that this is the best path for him? No. But I do think it's within character.
Awesome post, Sia! Kudos!

I agree about the rivalmance being borderline abusive, and I wish there were a way to distinguish between Hawke bashing all mages and just voicing disagreement with Anders' own decision to become an abomination. I also wish there were a way for Hawke's own opinions to change via the rivalmance without it breaking the romance.
When Anders reads Hawke his manifesto - when he bares his soul to the one person he cares about most, Hawke has two choices - admit that he may have a point via the diplomatic dialogue option, but that he's going about it the wrong way (which ends the romance), or shoot him down mercilessly, either by mocking his manifesto or telling him he's completely wrong.
I'm not saying Rivalmance isn't a valid option (imo, it's not the best option for Hawke, and it devastates Anders. I don't like playing characters with such conflicted romances, but that's just me, and I know many on this thread disagree, and more power to them!), but what I would like is a third path, where Hawke can change their own opinion about Anders' rebellion and the mages' plight. The stacking dialogue choices reset after every act, allowing Hawke to switch between sarcastic, diplomatic, and aggressive dialogue triggers as the story progresses, if the player deems it appropriate for Hawke to undergo a personality shift. I think romances should have the same option - a chance to slowly come around to the other partner's point of view, despite previously disagreeing with them.