Victini: Keep B+
Jirachi: Keep B+
Magnezone: Keep B+
Staraptor: B- -----> B
Starmie: Keep B+ (this, if you ask me, should drop into B-/C+, because it's too outclassed)
Weavile: B- ------> B
Victini: Victini is kinda predictable, weak to Pursuit and SR, and has no reliably recovery move, making it less effective as a stallbreaker than Mew in my opinion. Also, is Victini really as effective as Mega Aero in this meta?
I have no opinion on Victini, as I've never used it, but some things could cause it to rise. A)that bloody defensive typing. It can stallbreak AND it has these resists (Fairy, Fighting, Fire, Grass, Ice, Psychic, Steel) that something like Mew could only dream of. Resisting Fairy, Fighting, Steel, Psychic and Fire in a metagame like this is pretty bloody huge don't you think? 2) It fits on stall because it can counter 2 of the Mega Wallbreakers with ease and check the other one. And seeing as stall needs a stallbreaker to be effective nowadays, I can see it having a very good reason to be used, even over Mew.
Jirachi: Due to the prevalence of Knock Off, Azumarill and Zard X, this guy has no easy task doing its job in OU. Sure, it's a great Mega Gardy check, but I don't think it should rise into A-.
Jirachi, again, I have never used, but there's so much to say. 1) OML THOSE RESISTS. Dragon, Fairy, Flying, Grass, Ice, Normal, Psychic, Rock, Steel. It resists so bloody much that's so bloody good in the metagame rn and that's one of the reasons it fits so well on stall. 2) It's just a far better doublade, beating most of the Mega Wallbreakers and providing wish support, something nothing else can do. I don't know if it deserves to move up, but take what I've said into account.
Magnezone: It fits well on dragmag, birdspam and most offensive teams and hits hard as hell, but it has one sole job: removing steel-types. Until you realize Mega Scizor can get past it with Superpower and Shed Sheel Skarm/Ferro are becoming more and more common.
Removing steel types isn't this thing's only job, LOL. It's hard af to switch into (at least the specs set can be) and does pull it's weight even outside of killing steels, seeing as it's a good check to all the good bulky waters bar Quag and has a nice choice scarfed set (who may only 2HKO Ferro and Scizor but regardless it still wears them down enough to be easily revenged if 1 of them carries a way to beat this thing) that checks birdspam excellently. It has had a massive impact on the meta (it's why Skarm runs Shed Shell) and partners excellently with threats like Lando-T and MPinsir.
Staraptor: This guy needs to rise. It's a great partner to Talonflame in birdspam teams and has almost no true counters due to Brave Bird's sheer power. It's not as weak to SR as Talonflame, gets Close Combat and even Pursuit to try and trap -2 Lati@s or something.
I'm not going to argue here, as it does in my opinion need to rise.
Starmie: Starmie is kinda like Donphan in the sense that there are always better options for the job. Excadrill, Mega Blastoise and Lati@s if you want an offensive hazard remover, Greninja if special attacker, and Tentacruel if defensive rapid spinner. By this logic we should rank shit such as Donhpan, Uxie and Dusknoir cause they are pretty versatile, but at the end of the day have no reason to be used in OU. Starmie combines all these roles and is pretty good at them, but in no fucking way should it rise.
Ok, WHAT WAS THAT. Starmie OUTCLASSED BY ALL OF THOSE?! Ok, let me explain why this is just bullshit
Excadrill: Starmie is the best dedicated spinner in the game, while Excadrill is the most viable Pokemon with access to the move. Starmie checks far more hazard setters, has far better abilities as a spinner and has that top notch defensive set. While Excadrill pulls his weight overall far more, it's still not as good as a dedicated spinner as Starmie.
Mega Blastiose: Mega Blastiose would outclass Starmie, if it weren't for it's opportunity cost. This thing is a dedicated spinner that IS A BLOODY MEGA POKEMON. As a result, due to all of the other Mega Pokemon that are far more viable as they do far more than just spin all day, it's often hard to fit this thing on a team. By using it on a team, you are stopping yourself using a plethora of fantastic Mega Pokemon that you could still use by just using Starmie. Starmie, on the contrary, is easy to fit on offensive teams (at least I think so). Seeing as how important hazards are in the metagame: If you are using an offensive team with hazards, you don't run TTar and you have at least 1 or 2 Pokemon weak to SR (not uncommon) you'll be running Starmie a lot of the time because of how good of a dedicated spinner it actually is.
Lati@s: They defog, Starmie spins. One of them is redundant on teams with hazards, the other one isn't. Starmie has it's pros over them anyway, like Reflect Type (I guess Latias gets it as well but w/e) and Natural Cure. It's kind of unfair to use this as a reason to lower Starmie.
Greninja: Yeah, Greninja is so much better than Starmie at just being a revenge killer/special sweeper, but it can't spin.
Tentacruel: How is this a better defensive spinner than Starmie? Tentacruel lacks Natural Cure, reliable recovery, both of them are bulky waters using the defensive set so they are easily compared and Starmie has Reflect Type which allows it to work around far more. Tentacruel has less of an offensive presence. It might have a better defensive typing and more bulk, but if you ask me, Starmie > Tentacruel.
Starmie combines roles and is DAMN good at them, and it's no where near as awful as Uxie and Dusknoir.
I HAVE NO OPINION ON WEAVILE.