i have no idea if this is gonna be coherent but here we GO
so straight up, i didn't romance fenris the first time i played and i had a bad time with DA2 the first go around and didn't get close enough with most of the characters to have a strong impression of them (fenris included), but @redredribbon convinced me that fenris was where it's at and that i should give it another go. so i did and now he's got my nuts in a vice
second point, i play mage when i romance him bc i like the added flavor but non mage hawkes are also good. i always friendmance him because i don't really like the rival path with him. and it's extra difficult with a mage hawke but that makes it more worth it to me lol
without getting too deep about it, i was processing a lot of unresolved trauma when i played that game and playing through fenris' storyline in depth made it hard not to over-relate to him, albeit through that fantasy lens. there's a lot of really hard hitting stuff in there about feeling like something horrible that happened to you however many years ago has so irrevocably changed who you are and how you relate to the world that the person you were before might as well be a total stranger, and the bitterness that goes along with having been shaped or even created by something you hate.
but the thing i really, really love about his romance is that his positive growth and change is not dependent on hawke. he is clawing his way out of his bad circumstances and changing his life with or without hawke. hawke can be a positive catalyst for change, a push in the right direction, and a source of joy in his life, but he doesn't need hawke to heal. it's just that the healing is what enables him to allow himself happiness, to choose to be with hawke.
and the moment in the romance i love most, which i guess was controversial with some fans, is the moment in the romance where he leaves you. because trying to be with hawke has triggered him and he recognizes he is not in a place where it is healthy for either of you to continue, he has to put up a really hard boundary. and in the time he spends away, he gets better. he wallows less. he makes friends. he finds out who he is, baggage and all, and makes the decision to live with it and move beyond it.
and you have the choice to wait for him or not, but at the end of it, if you're both still on the same page, he's with you 100%. i thought it was just really beautiful. the absolute antithesis of "my love can heal him". he can heal himself. he can build his life back, not the same as it would have been if he'd never been hurt, but still his. and he wants hawke to be part of that.
aaaaand another reason i love it is because i have a major thing for the characters who are so used to being a tool for someone else's use trying to recalibrate when the person they offer themself to isn't trying to use them or treat them like an object. the whole process of learning to be a person again and expecting people around you to take advantage of you and meeting the person (or people) who just defy every expectation you have. (this is the same reason i go bugfuck over zevran and iron bull, i have a type)