Alright I'll go through the pokemon I've used. Will be short descriptions since there are a lot.
Very good specs user, can ohko most offensive pokemon that don't resist boom burst and destroys most stall if you can trap chansey (hint gothitelle). Although slower and slightly less powerful than Chatot it is not stealth rock weak and can actually take an attack meaning it needs less support. Better coverage options as well in fire blast/ focus blast.
B+
Ninetales actually has decent stats now and with a heat rock can actually be used on a sun team. Obviously not as good as rain but I'm sure sun has potential.
C+
Tried using on a sun team and does not disappoint if you can keep sun up. 115 sp atk with solarbeam weather ball and sludge bomb, as well as potential boosting with growth and the only safe switch ins are heatran and the pink blobs.
C+
I used a rest talk set with superpower to some success, very average before any boosts though so
B-
Surprisingly powerful and can annoy potential switch ins with chatter confusion for free subs. Lacks any sort of bulk though.
C+
A pretty reasonable wall, stall breaker or rock setter. Suffers against some physical attackers.
B
Kabutops is probably rain offense's main threat. Huge amounts of power and speed with the only limitation being politoeds support and 7 turns of rain max.
A
Not as threatening as Kabutops but still good in rain. Can ruin counters with a scald burn and recover somewhat with giga drain.
B
Actually a very nice spiker just now, can annoy a lot of stuff with leech seed and spiky shield.
B+
Provides defog and good physical walling for stall teams. Can set up Stealth rock or spikes.
B+
Still threatening with dragon dance and the sp def wall is a decent choice for stall teams as well to switch in to stall breaker mew.
A-
Fairly decent spinner, between scald toxic and acid spray its actually pretty troublesome to switch into. Lacks recovery however and poor physical defense.
B-
Nice stealth rock setter with good physical bulk and filter to survive near any unboosted physical attack. Definition of a tank really as it can hit back hard as well.
B
Still a good wall for stall teams or a tank with max sp atk for balanced teams.
A-
Solid unaware user, cm booster, rock setter, heal bell and wish passer depending on what you need. Versatile and good typing. Can find itself lacking bulk in this more powerful meta however.
A-
Decent specs user thanks to volt switch, cm is alright as well.
B
Great cm user that is hard to stop without trick, taunt, or very powerful attackers. Even water absorb etc can be stalled out thanks to rest and pressure.
A-
Thats most of what I have used extensively which isn't ranked yet. Forgive the short descriptions, if you don't agree with anything feel free to ask for a better description ( i can probably drag up replays as well), also a lot of the ranks were hard to decide since comparing pokemon across such a large pool of viable pokemon is difficult. If I were you
insanelegend I would rank as much as possible by yourself without bothering to give reasons, and then let people suggest changes. This is what happens in the other viability threads and speeds things up greatly. I know this will be harder than other tiers but give it a bash and I'm sure anything that is off will get picked up by someone.