I am an unusual case, in terms of emotional attachment.
On one hand, I got attatched to Midna during my playthrough of Twilight Princess. Then I realized that this is normal, because other people felt the same way, and I just rolled with it. Lol.
Midna really IS a well-written character, imo.
Then there was Legion, Wrex, and Grunt from Mass Effect, one of which was kinda short-lived(Rest in peace, my many-minded Geth friend I knew for only a few missions). My attatchment to Grunt and Wrex may not be strong today, but it's still there, I tell you what. Hell, I'll answer to Grunt like it's my name, and the brutish nature of the Krogan in general just makes me want to root for them.
I like my brutes, lol.
Then there's Nightmare from SoulCalibur (4 and 6, to be specific). Less of a case of being emotionally attatched, and moreso being a literal fanboy. Soul Edge in 6 is badass in design, and Nightmare's design in 4 is the best one I can think of imo. The things he says, the things he does, his origins as an alter-ego of Siegfried personified as an azure knight with a monster arm?
That's all I need to go from normal to MORE! I WANT MORE!
If I could main him, I would. But SC6 is littered with cheaters, iirc.
Then finally, the lake guardians. The lake trio from Pokémon gen 4.
Idk how or why, but playing Pokémon Diamond apparently got me attatched to three insignificant fairies to the point that I just made a cringey and gross OC out of them. No, several cringey and gross OCs out of them. And that was back in 2019-2020.
They somehow managed to water down my dragon obsession, for some reason. And I keep forgetting why I got so emotionally attatched to them in the first place.
I sometimes believe I am beyond my own comprehension.