I never like stuff like what they did with Aveline and Samara. Im all for raising the difficulty for certain romances, so many romances are way too easy these days, but to make them completely impossible is terrible, and defeats the whole point. Its like making an 'optional' boss fight, with a boss character that can't be beaten no matter what, its both annoying and completely pointless. And certainly a shame as well, as Aveline and Samara did have some real potential.
However the experiences, particularly the one with Aveline, could serve as a source of inspiration going forward. Suppose one of the characters that you meet and becomes a member of the team, is engaged to some random dude, and you subsequently learn that the engagement is to promote peace between their two lands. You would have to both win her heart away from said random dude, and convince her that her own happiness, and your relationship, is more important than going through with this wedding that would benefit her town/city/whatever. Ultimately if you succeed, the dude would challenge you to a duel, and it would be a legitmately challenging fight. Finally after all that, you could have as a final 'quest', to bring about the same peace between the two lands, that would've happened if she had married that dude. Perhaps via diplomacy, perhaps some booties would need kicking, but ultimaetly peace and happiness would reign in her homeland, and the two of you could be married and live happily ever after. Obviously if this were like the Samara/Aveline relationships, the storyline would end after you win the duel, with her feeling guilty that she didn't play her part to bring peace, and she ends the relationship, but of course that once again would be a vastly inferior ending that would make no sense. Hopefully they stop doing terrible endings like those. Challenging is good, as far as Im concerned the more challenging the better, just so long as there is some way to actually succeed, then all is good.
And yes, on an earlier point, Bethany should definitely return as a teammate and an LI, she was by far the best and most attractive character in DA2, and if she hadn't been Hawke's sister, and had been an LI, no doubt she'd have been the most romanced character in the game. Certainly in DA3 we won't be playing as Hawke, so there would be no 'sister' issue, it would just be romancing a beautiful and intelligent and awesome girl, who just happened to be related to somebody famous. Although in my DA2 game, I set her up with that nice mage girl that Anders almost kills, so even if we don't get the chance to romance Bethany, I can still happily imagine her living happily ever after with that nice mage girl, whose name I can never remember

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