That’s an awesome way to compare the scenes!
spoiler
You made me realize that, while Ainz has some character development, he doesn’t go through nearly as much as Rimuru does. Same with most of the companions. There’s plenty of character development in Overlord, especially with like Sebas and Brain, but a lot of Rimuru’s companions go through multiple complete transformations of their bodies and their personalities adapt to that, just like Rimuru himself. Full transparency: I’ve only watched the anime for each series, but I plan to read the novels when I get around to it lol.
Also forget Shion, Megiddo gave us my boy Diablo! :P
We Were Here and its sequels seem like the perfect slowish paced coop puzzle games for you guys.
Operation Tango and Escape Simulator are similar and also great.
A Way Out is similar to It Takes Two, with a more serious story.
Monster Prom/Monster Camp and The Yahwg are co-op visual novels.
Clandestine is a Co-op stealth game where one player plays as a spy, fps style, while the other plays as a hacker providing overwatch by controlling cameras and doors, giving directions, etc.
Keep Talking and Nobody Explodes is another asymmetrical co-op game where one person is trying to defuse a bomb by solving puzzles and the other is trying to help by reading the manual. The defuser has to tell the other person what’s going on so they can give the right instructions, much sillier than it sounds.