Fine lets play your game. Spore and regen, cute. So what exactly does it beat 100% of the time that warrants B-rank?
Perhaps you just don't understand the meaning of B-rank. Nobody is saying that amoonguss can beat Thundurus-T 100% of the time, probably the only thing that can beat it 100% all the time under optimal conditions would be gastrodon. But that's about all it can do. Now, if you think that amoonguss is beaten 100% of the time by
Modest, Life Orb Nasty PlotThundurus-T 100% of the time, you're correct. But, as you can see here....
Thundurus-Therian
Timid:4/0/0/252/0/252 34.728%
Modest:4/0/0/252/0/252 22.660%
Timid:0/0/4/252/0/252 12.996%
Modest:40/0/96/252/16/104 6.140%
Life Orb 26.106%
Nasty Plot 25.429%
But, as you can see here there's a bit of variation with Thudurus-T, isn't there? You honestly can't tell me that every single Thundurus-T runs life orb modest nasty plot, and even the ones that use nasty plot don't always use LO + modest. Every other set of thundurus is beaten unless there is some prior damage, but let's let amoonguss have the best conditions for once, shall we?
To remind you,
nobody said that amoonguss is better than celebi, is an amazing wall, or can beat thundurus-T 100% of the time. Your entire argument seems to be "it doesn't beat the things it's supposed to beat!" But it does; it just so happens that specs keldeo and LO modest nasty plot thundurus-T are things it is not supposed to beat.
Using gastrodon as a counter for thundurus-T and saying that makes it a better poke entirely than amoonguss is a terrible argument. Hey, cloyster can boost its offenses and speed at the same time and have near-perfect coverage and terrakion can't! Terrakion is a shit sweeper! That's exactly the kind of argument you're trying to make, albeit a bit exaggerated.
Gastrodon and celebi are better rain checks in general than amoonguss but to put it frankly amonguss can help support its team in some other ways. Spore, for one, is really just that good. The ability to incapacitate another pokemon almost completely is a really good ability. Even after spore is used, it doesn't become useless--it can use double powder to incapacitate more sweepers, such as garchomp or landorus that would not normally fear paralysis. Any attack that does not straight up deal about 40% to amoonguss results in the user being able to just switch in and absorb the damage with no consequences, which is incredible for a pivot.
That's what amoonguss is, a pivot, not a total rain counter like you think we think it is.
1. I already explained how it loses to keldeo.
2. Factor SR and LO in that Thunderus-t calc and come back to me.
3. If toxicroak carries as sub, it loses.
1.
MODEST Specs Keldeo in the rain, used only 10% of the time with modest in the first place. Did you know celebi also loses to modest specs keldeo in the rain?
2. See above
3. wut
We're not making out amoonguss to be some kind of god wall, but it is an excellent pivot with spore and regenerator. It's just good, not that good, but good.