Treecko for Mid-S because Top-S is where Pokemon are more prone to be banworthy! :D
Anyways, I'm actually really excited to be splitting Pokemon into High, Low, and Mid within their own tiers. This is great for newer players to see top threats in the metagame, and it's more defining than just lumping all Pokemon together into one huge ass group. It also gives us the opportunity to think about every Pokemon in each ranking on an individual level, and it might help us find Pokemon that are more worthy of lower or higher rankings. Let's do it boys (and girls if there are any who actively post in this thread)!
Kangaskhan is sort of a strange Pokemon. It pretty much does one thing, and the one thing that it does hardly makes it broken. But of course, the viability rankings aren't about what is broken and what is not. Kangaskhan is a really great revenge-killer and backup plan against a lot of other top tier threats. It's a great way of having a revenge killer without having to worry about running a super-fast Choice Scarf user, and it has a lot of great power behind its two priority moves—Fake Out and Sucker Punch. Whenever I play with Kangaskhan, I usually think "when all else fails, I still have Kangaskhan." It's sort of offensive support, and it's well worth a spot in Top S-Rank to me.
Scolipede is in my top three favorite Pokemon to use in this metagame, alongside Kangaskhan and Swellow, and it's pretty easy to see why; it's so good. I kind of felt like this one was a no-brainer, but Raseri does make some good points for Mid S-Rank. Base 90 Attack seems a bit underwhelming, and its bulk isn't stellar. But it does have a couple of great resistances that let pair well with the likes of Seismitoad, Carracosta, Kangaskhan, etc. I think the key point here is exactly what tennisace said: it defined an entire playstyle in NU, and that playstyle—Spikes-stacking offense—is such a good one that I think it slips into Top S-Rank for me.
If my hate for Jynx wasn't already known by everybody, let me add it here. The reasons why I hate her are the same reasons why she is deserving of Top S-Rank, and they are reasons pretty much everyone else already listed. Jynx might struggle a
tad bit against opposing offensive teams, but that's pretty much it. It has three really great sets, and all of those sets have different variations where you can change them for what your team needs. Lovely Kiss is ridiculous for a Pokemon like her, in the same way that Sleep Powder only helped Venomoth get banned from RU and helps make Lilligant a top-tier threat in RU. Jynx makes stall a bit of a liability in NU, forcing such playstyles to run multiple checks to Jynx. Otherwise, the only check you run can be put to sleep. Same type of thing goes towards balanced teams. Basically unless you never give Jynx the opportunity to come in for free, you'll be fine. But that's incredibly difficult without running hyper offensive teams. There's no questioning Jynx's spot in Top S-Rank.
The BW starters have always seen some success in BW NU, and Samurott is truly no exception. Water is such a cool offensive typing, and Samurott has all the tools in needs to play successfully in NU; it has great mixed attacking stats, an easy-to-utilize movepool, cool bulk for an offensive Pokemon, and enough Speed to outpace nearly every wall in the tier. What holds it back is also its Speed, though. Most of the tier's best offensive Pokemon are faster than Samurott is, and most of the tier's offensive Pokemon that are slower than it is have better bulk. Priority patches up its Speed a bit, sure, but it's incapable of beating Jynx, one of the most common Pokemon in NU, unless it switches into a Megahorn from either of its popular sets. In general, anything that can outpace it and take a +2 Aqua Jet usually plays well against it and can come in and revenge kill it. Undoubtedly a Mid S-Rank Pokemon, but its Speed pretty much is the only thing holding it back from Top S-Rank.
Toooooader. I love Seismitoad right now. Basically what Raseri said sums it up: it can play basically any role you want it to, and it does all of these roles at least decently well. Seismitoad is a Pokemon you can just slap onto most teams without much hassle. If only it was a little bit faster or a little bit bulkier or a little bit stronger, it would be Mid S-Rank. To be honest, its versatility almost makes me want to push for it to be Mid S-Rank, but I do realize that versatility alone doesn't cut it. I'm fine with Seismitoad for Bottom S-Rank, but I highly encourage anyone who might want it to be Mid S-Rank to make their arguments. I could be convinced to change my mind!
Carracosta is such a cool Pokemon, and I'm glad we could mostly all come to agree with its spot in S-Rank. I still occasionally doubt its position in S-Rank from time to time, but then I play with it again and realize why it's here. Everyone else has already covered why it's Bottom S-Rank, and I agree with them for those reasons—doesn't hit
quite as hard as you might want, not as bulky as you might think, still pretty slow after a Shell Smash, etc. If anyone wants to know why it's S-Rank in spite of these reasons, read about half the thread. It's in here. ;)
Recap of S-Rank in order of worthiness in each ranking:
Top S
Jynx
Kangaskhan
Scolipede
Mid S
Samurott
Bottom S
Seismitoad
Carracosta