I am all about stories where the hero and villain know each other very well and were once friends, but I could deal with it being used another way.
What if instead of being used for drama, for wistfulness and pleas to join the other side, it was more like the hero looking over a battlefield going Seriously, who does she think she’s kidding, she’s been using the same chess strategy since we were seven or the villain picking a headquarters in a specific climate because she knows the hero hates hot weather or deciding Send in some forces to round up all the copies of his favorite poet’s work, that’ll tick him off.
Or most of all them still having inside jokes with each other.
Tbh i headcanon that part of the reason the Elrics were so good at alchemy was bc they had a sibling. With siblings nothing is free. Equivalent exchange at its finest. I just traded half a bottle of soda for the use of my sister’s earbuds on the way home. She brought up the fact that she gave me a drink while I was laying on the couch two months ago in order to convince me to bring her snacks. The Gate of Truth doesn’t have anything on a younger sibling who wants something and did something nice for you a couple years ago
Speaking of subverting expectations, a great example of good subversion of expectations is Aranea Serket becoming the main antagonist for an entire arc.
Nobody expected that. We were in the middle of a confrontation with the Condesce when suddenly a new player comes into the mix seemingly out of nowhere and messes up the entire board.
But it wasn’t out of nowhere. The motivation, means, and timing for the twist were all laid out beforehand, so when Aranea took that ring and entered the Alpha session, it made sense.
It subverted our expectations because we weren’t paying attention, because we were engrossed with the main plot. Not because it was something we couldn’t possibly know or expect since the writers made it up on the spot.
It was a great twist because up to that point she had presented herself as nothing more than a dork who was desperate to be seen as helpful, but there were also neon flashing signs saying “You should expect this character to have a similar personality to Vriska”. The twist was the reveal that her need to be helpful was really the same character motivation as Vriska’s need to be important, and she turned out to be the same but worse. And afterwards you could only realize that of course she’s the same kind of person as Vriska, you should have seen it coming but didn’t.