Tyrian and Watts are interesting to analyze from a writing perspective to me because they both succeed where the other fails.
To elaborate on what I mean, there are two metrics I use for forming my opinion on RWBY characters: how well they incorporate the character or story that inspired them, and how well that concept is executed in the writing. Tyrian and Watts both succeed in one category but struggle in the other, in my opinion, but the categories they succeed and fail at are opposites of each other.
Tyrian is possibly the most 1:1 translation of his inspiration in the entire show. He is meant to be a reference to The Scorpion from The Frog and The Scorpion. The entire moral of that story is that the innately malicious nature of people like the scorpion is to actively harm others even when doing so is objectively detrimental to their own physical wellbeing, and Tyrian is a sadomasochistic, nihilistic serial killer scorpion man that worships a woman who wants to cause the apocalypse simply because he loves pain. But the problem is the execution of his writing is...pretty one note. I don't necessarily mean that he needs more depth or complexity, the fact he is the only one among the villains that is purely in it for enjoyment and not any deeper personal reason (Hazel blames Ozpin for the death of his sister, Cinder is desperate for the power and agency she was denied in her childhood as a result of enduring abuse and poverty, Mercury and Emerald are loyal to Cinder because she preyed on their need for community and support, Watts feels snubbed because Ironwood chose Pietro's idea for protecting humanity over his, even Salem herself just wants the pain of her immortal existence to end) is clearly an intentional part of his dynamic with the rest of Salem's group, and evil for the sake of evil villains can be fun. No, the problem is that the specific ways he's evil for the sake of being evil are almost always kind of boring and repetitive. A solid 80% of his scenes are one of two things:
A). Sadistically taunting a hero mid-battle when the hero is trying to subdue him.
B). Antagonizing any villain that isn't Salem, while openly praising Salem in a way that is very overtly religious in nature, usually ending with the other villain walking away in disgust and fe ar as his cackling echoes ominously in the hallway.
To be clear, these scenes are not badly acted or even on their own badly written, but it is the law of diminishing returns. Spamming something good risks making it less good the more you rely on it.
Watts is, as his name and occupation as a doctor suggest, very loosely based on Dr. John Watson from the Sherlock Holmes books. Except, that name and occupation connection is literally all he has, and he's not even the right kind of doctor. Watson was a medical doctor, not a computer engineering doctor. Basically nothing else about Watts' character communicates this inspiration.
Admittedly, some change between inspiration and character was always sort of necessary. The central theme tying most of Salem's inner circle (outside of Tyrian and Salem herself) together is the fact that they're villains who's inspirations were the heroes of their stories. But the difference is, the motivations behind their villainy are still rooted in the story that inspired them to varying degrees. Hazel is Hansel from Hansel and Gretel after being consumed by grief at Gretel's death, Cinder is Cinderella if the abuse from her mother and stepsisters caused her to snap, Emerald is Aladdin if Aladdin was desperate enough to survive to fall into a bad crowd, etc. Even Mercury reflects his inspiration better through his continued friendship with noted thief Emerald (the Roman god Mercury was the god of thieves) and the emphasis his fighting style places on his feet.
Watts is Watson if he was a catty, egotistical tech bro. You see the difference? That's not really engaging with anything about Watson as a character. I'm half convinced the only reason the writers claim Watson as inspiration for Watts is so they can use the pun about electrical watts in his name.
But, in terms of the actual execution of the character, Watts is really well done. He oozes charisma and his general wit makes him steal the show in almost any scene he's in. He's such a smug asshole that hating him is unreasonably fun, which makes it all the more satisfying when he gets his shit rocked physically.
It also helps that he is, y'know, has things to do beyond Be Vaguely Creepy.
