You could do this the Phantom Blot and/or Sylvester (whichever you have more for)...
But how do you see their relationship with the other villains?
I will do Sylvester... because as much as I love Blotty, I feel like I don't have much to add with the Blot conversations, my thoughts are more or less the same.
But boy do I have thoughts about Sylvester relationships!
Alot of thoughts! Even those outside the villains..
But let stick to villain only..
Let's start with Pete- now it's no secret i ship him with Sylvester, but shipping aiside they do objectivity have a genuine friendship once we get to great orphanage robbery . They get drinks, make jokes, do little dances, and overalls enjoy causing a bit of choas together.. albeit the only problem is Sylvester's ego leading to the occasional insults. I always low-key headcaon this also a bit of self-defense mechanism, Sylvester doesn't want to seem like he has any weaknesses or his fond of someone who isn't the brains . After all,He know how easy it is to exploit people from frist hand experiences.
Which leads to his relationships with the other villains..
Sylvester and Blot haven't have a real comic together really, but Sylvester did mention him and it would be weird if they don't at least known eachother at bare minimum. I can see Sylvester respecting Blot somewhat, but not being above betraying him when the chips on his side, Sylvester isn't really the type to be boss around, he far too ambitious to not try star screaming someone.. (which weirdly my only issue with his characterzition in zombie cafe) though would still try to have his cake and eat too by trying to retain a somewhat positive relationship with Blot, knowing how much influence he has.
Sylvester will be less inclined to do so with Vulter though, as utterly terrifying and powerful Blot can be, Sylvester know he at least have Pete between them to act as middleman and also Blot prefer not seeing any blood.
Vulter however have weapons of war and army.. he do whatever it takes not to piss off the man with an army who is more then fine with blood. Of course ,f everything goes right, Sylvester is more then willing to try to get a edge above him, but for the most part he's trying to have a friendly reputation with him.
Squinch is a weird one, they probably would be killer business partners together, Eil swindling people with his charms while Sylvester trap them in predatory contracts, a win-win , only problem which one them is going backstab the other the frist.. will Eil get too greedy or Sylvester to close to the sun? That one of the key difference between them, Sylvester is more likely to expand his plans while Squinch is fine with just getting his bag bigger.
Trudy and Sylvester haven't meet, but in my hearts of heart, they get along just fine most of time.. even if Sylvester is still a little asshole.. (which Trudy finds funny).
I don't think Sylvester would be as fond of Scuttle though if they ever actually work together properly.. but he does know having a wildcard under your belt doesn't hurt..
Portis.. honestly it kinda strange to imagine these two together.. Sylvester's smart but he's not tech or cem smart like Portis.. he would enjoy talking to him but weirdly enough, he still like Pete more even if he'll never admit it.
Doublejoke- God Sylvester would find him annoying.. lol. While Sylvester isn't a stick in the mud, he's know Doublejoke has doublecross people before..with his little gimmicks..
Miklos- God i want this team up to happen so bad please, please.. they share sheer hatred of Mickey would move mountains- but yeah outside of both hating Mickey, i think at best Sylvester find Miklos amusing, he loves when Mickey life is ruined after all, but at the same time he won't trust him due that fact he can pretend to anyone, not just Mickey..
Rhymes- "would be. A good asset but I do not trust him and he's creepy as hell, i will keep my distance."
Ecks, Doublex, and Triplex- Weirdly a mutual respect.. it might have to be because they have mind control and Sylvester rather have them on his good side.. another situation like Vulter but Sylvester was much less afraid of them.