I see a few odd things, but for the most part it looks pretty good so far. Hopefully this isn't stuff everyone said on page 1 or 2 or soemthing like that.That being said,
Sandslash up to B rank
Sandslash is one of the best spinners in the tier right now. With great physical bulk, the ability to hit up most spinblocking ghosts supereffectively with a knock off, a solid support move in stealth rock, and a notable niche in sand sweeping with a Sand Rush set, this pokemon really doesn't deserve to be C rank. With 100 base attack and 110 base defense, it can both eat up physical hits and retaliate with stab Earthquakes. This combination of offensive power, team support, and physical bulk makes Sandslash a good pokemon to consider for a team when you want a spinner/defogger, and I believe this warrants a higher ranking then what it has now. It really doesn't belong all the way down there.
Weezing up to B- rank
Why is this all the way down in C- rank? Weezing is a great physical wall, able to deal with common fighting and ground attacks, able to stop set-up sweepers with moves like Haze and Clear Smog, damage steel types trying to get free switches with flamethrower/fire blast, recovering hp with pain split and black sludge, support the team with toxic spikes, and burn physical threats with will-o-wisp. It shuts down a lot of notable pokemon, isuch as Hariyama and Primeape, while also whittling them down with sludge bomb, will-o-wisp and pain split. Want a good check to Sawk and counter to most fighting types in the tier, a solid physical wall, or just a good pokemon toxic spikes support? This is a Pokemon that can fit those roles easily. Lack of reliable recovery does hurt it, but it's still a very solid pokemon that can cause a lot of issues for your opponent.
Carracosta up to B+ rank
Looking down and seeing this down below Barbaracle is just disappointing to say the least. I would say that this pokemon is infinitely more threatening then it's fellow water/rock smashers, especially Barb. While it is slower, and therfore can be dealt with by scarfers, you'd think, that really isn't the quite the case. Unlike Barb, this pokemon learns Aqua Jet, giving it a solid STAB priority move. Add in a 2 solid(heh) abilities in Sturdy and Solid Rock, making it fear supereffective moves much less. These two abillities also allow it to carry weakness policy, giving it a possible +4 attack/special attack stat. Trying to revenge this thing with your scarf primeape?
+4 252 Atk Carracosta Aqua Jet vs. 4 HP / 0 Def Primeape: 261-307 (95.9 - 112.8%) -- guaranteed OHKO after Stealth Rock
Raichu?
+4 252 Atk Carracosta Aqua Jet vs. 4 HP / 0 Def Raichu: 279-328 (106.4 - 125.1%) -- guaranteed OHKO
Typhlosion?
+4 252 Atk Carracosta Aqua Jet vs. 4 HP / 0 Def Typhlosion: 422-500 (141.6 - 167.7%) -- guaranteed OHKO
As you can see, quite a few common scarfers can be killed by priority aqua jet easily, if you can get it pulled off, which isn't very difficult to do with the amount of weaknesses Carracosta has. At +2 Speed Carra can also outspeed most of the tier, beating out timid/jolly nonscarfed base 110s. It can do massive damage with STAB Waterfall, Stone Edge, or Rock Slide, as well as carry decent coverage moves if you prefer, such as knock off and earthquake. With a okay special attack stat of 86, you can also run mixed or special varients to lure in physical walls. It's third ability, Swift Swim, is also useful, and gives it the potential to basically kill everything on rain teams, though it's by far the worst of the 3.
While Carracosta does have some notable flaws, such as needing hazards cleared from it's side for the sturdy varient to work, liking rocks on the opponent's side, and being unable to do much to Seismitoad or Poliwrath typically like it's fellow smasher Barbaracle, it's still an immensely threatening pokemon, and I feel it's just as big of a threat as it's water/rock shell smashing brethren.
Simisage down to D rank
Simisage is pretty worthless, with a lacking movepool, and little niche. You're much better off using a pokemon like Lilligant, Shiftry, Cacturne, Serperior etc for your grass set-up sweeper.
Simipour up to C rank
Easily the best of the Simi trio, and the one with the biggest, most worthwhile niche. Not much really competes with it as a special water sweeper, and Omastar is quite a bit different than this monkey. With both Sub Nasty Plot and 3 attacks Nasty Plot as viable sets, this pokemon simply sets up nasty plot, perhaps tries to trigger a salac berry to outspeed certain scarfers and/or hit torrent range. While it is fragile, it has a decent amount of power and speed, and water/grass/ice coverage that hits everything neutrally, I believe. Also, it has a viable mixed set and even such gimmicks as endeavor. All in all it's still a solid, good pokemon, and not something you should ever underestimate.
Aurorus up to C- rank
Whenever I fight this thing, I am immediately surprised by how strong it is. Even scarfed, a 1.3x STAB tri attack hurts. Add in that it can't be sucker punched, and it starts to get scary. With Rock Polish, it can attempt to sweep, and it can go both physical and special with options like Toxic Orb Facade. It quite honestly hits like a truck.
252+ Atk Refrigerate Aurorus Facade (140 BP) vs. 4 HP / 0 Def Sawk: 292-345 (100 - 118.1%) -- guaranteed OHKO
252+ Atk Refrigerate Aurorus Facade (140 BP) vs. 4 HP / 0 Def Magneton: 120-142 (49.5 - 58.6%) -- 99.6% chance to 2HKO
It still has lots of flaws, being easily revenged and dealt with by pokemon like Hariyama and Gurdurr, and having an SR weakness and no good special rock STAB. That being said, underestimating how strong this pokemon is can lead to you getting destroyed by it.
Dusknoir down to E rank
This pokemon lol, is so incredibly bad, that even D rank isn't low enough for it. It has nothing that really should draw you to it. Want a powerful physical ghost type? Then use the stronger, better Golurk, or the bulky, strong and versatile threat that is Spiritomb. Want a pokemon that tanks hits, burns stuff, and perhaps uses Pain Split? Then use Gourgeist, Spiritomb, bulky Rotom, or even it's almost as bad pre-evolution, Dusclops. Even it's Trick Room setting abillity is outclassed by Gourgeist. There is literally no reason to use this horrible waste of a team slot, or it's pre-evolution, but at least Dusclops is better than this horrid mon. Seeing this next to at least passable mons such as Lopunny, Stunfisk, Rapidash and Rampardos is just wrong.
Steelix up to B- rank, or at least C+
While Steelix does have it flaws, such as a lack of recovery and pitiful special defense, it's still a very solid pokemon, and fits well on many teams, especially those with an Audino or Lickilicky to support it with wish, but it doesn't need that to function well. Steelix is a great physical wall, sporting 200 physical defense, the great defensive typing of steel, and having good support moves such as Stealth Rock and Roar, while also managing to have 2 great abillities in Sturdy and Sheer Force, a threatening presence with sheer force boosted iron heads and STAB Earthquakes, and the abillity to switch into a lot of physical attackers. Having trouble with Swellow? Maybe Granbull? Or Kangaskhan? How about Armaldo? Perhaps Regirock? This pokemon can come in and either force them out and punish what comes in with one of it's STABs, force out the oncoming switch-in with roar, or just hit those pokemon with an powerful attack. Never underestimate how good Steelix is at eating up physical hits.
Regirock up to B- rank
Regirock is a godly tank in the NU tier, with 200 physical defense, 100 special defense, and 80 hp, defensive stats most pokemon can only dream of. Furthermore, it also has 100 attack to pound things with STAB stone edges, as well as earthquakes, drain punches, fire punches, thunderpunches, and ice punches, as well as possiblly paralyzing them with T-wave and providing Stealth Rock support to a team. With two good sets in AV tank and Lefties support, it can provide your team with a bulky and powerful pokemon that can deal with a lot of NU's threats. Assault Vest Regi can eats hits for days on both sides, while hitting hard with moves like Earthquake and Stone Edge, and recovering hp with drain punch. Even uninvested, 200 physical defense eats physical hits up. Certain Regirocks can even live Banded Sawk's Close Combat. Regirock is also a decent mon to carry on sand teams, as it can both set sand, and profits from the special defense boost. It's also a nice pokemon on sun teams, if you want a pokemon that can set weather multiple times as well as set rocks, having a niche over it's rock/ground type competition in Golem, who is typically knocked down to sturdy from one hit and killed in 2, and who also has a lot less bulk than Regirock.
I think that's good. For now, at least.