Most of his personality/etc. there applies to his AU version as well!
Valentine Adelaide (full name Valentine Vivien Adelaide) is a 26 year old Hitman for the Lammergeier Syndicate. That is, until he died several years ago. During a particularly tumultuous assignment he was murdered by a rival gang member, despite rarely making mistakes before and being at the top of the syndicate. He didn't think it was possible for him to die most of the time, anyways.
Out of everyone, Aurelio took it the hardest. He couldn't imagine a life without him after living together for 9 years. And in a way, he didn't really need to live a life without him. Due to new developments in technology, it was possible to plant Valentine into a new body, albeit without the gruesome memory of how he died. And he was reborn as a "Kittybot", a catlike robot species, with ears and tail and all. He was retired from his Hitman position to stay home, almost like a housecat. He's more delicate in this form and Boss doesn't want to repeat the past.
Knowing the real Valentine died and was replaced with a robot programmed to act like him bothers Aurelio just a little bit, but other times it makes him flat out depressed. Even if he acts more or less the same, nothing can truly replicate who he was to him.
When he was made he was intended to have two eyes, fixing his previous lack of a second eye. But upon activation having a second eye made him panic enough that he clawed his right eye out again, now becoming the same as he was as a human. He insists on not getting a replacement.
He remained mostly the same person, he just has... Catty tendencies. Bites Aurelio more than ever. Hisses. He somehow got even more ill-tempered. But in the same vein, he also got more affectionate and clingy than his already unbearable amount. He even loves all the things he used to like his hamburger addiction, but he can't help but be a little upset about his new Barbie anatomy. He manages... He just wants more petting in return.
He still has self-destructive tendencies, in this form its been redirected to chewing the end of his tail and forgetting to charge his battery. Unfortunately stuff like this can't be programmed out, same with his issues from when he was a human. Even if he technically isn't brain-damaged in this form, it transferred over regardless, keeping him "mentally stunted".
Boss is happy he's back, but dear god sometimes he wishes he wasn't.
Boss is the one who designed how his base form looks. Taking into account he memorizes the things Valentine likes religiously, he did a good job.
Aurelio also learned some programming to be able to keep up on his maintenance and adjust things, despite being previously inept with computers. He can do the basics.
The hearts on the backs of his ears are practically an arrow pointing to where he likes to be pet.
Camilo is bad at petting him (he's used to cows), but he can't tell him even if he's overstimulated... He's too nice to tell him.
He still sits in Aurelio's lap like a roach even if he weighs a ton due to the whole metal body thing.
Valentine's death basically made Boss have Super-Ultra-PTSD. Sorry sir