Old topic, but still relevant due to the recent ban on Tenma.
Switching in an offensive oriented puppet will most likely lead to death, so that basically leads to Special walls with Toxic being the only dedicated answer to Her (someone please tell me how much of an idiot I am for writing that).
Yes, you're an idiot. :<
(okay, not really)If you do that, then Tenma can just Sub, set up on your face (with either Agility or CM) and wreck your whole team.
An offensive mon could deal with that kind of set, but then you risk getting paralyzed, having pretty spikes blown away, or just plain walled.
And if you try to spinblock you still run the risk of being... well, wrecked, so people would probably never spinblock you, effectively making her the best spinner in the game.
Hence,
Assumed to be uncounterable until you've uncovered what kind of set she's running, and by that time it's usually too late.
She's not just
assumed to be uncounterable until you know what she runs; she
IS uncounterable until you know what she runs, unless you're the king of gambling or something.
Even the two counters you suggested, SKomachi and Cirno, just die anyway if she's running a standard defense/support set. And it's not like support Tenma was uncommon back in the day, since if you run her with Whirlwind/Twister/Roost/TWave and a defensive spread, you have pretty much
all important support roles - except for spiker and cleric, which aren't absolutely essential depending on your kind of team.
Then, SKomachi/Cirno switch in, get a t-wave in their face, Tenma switches out and laughs. Both of these are pretty much already dead weight if they're paralyzed, and if the team running Tenma has Wish support... yeah, things aren't pretty.
But then... couldn't SKomachi/Cirno break her if they ran Lum? Sure, that works against support Tenma, but offensive variants just beat you anyway if you're not running Swimsuit/Fur Coat, remember?
Oh, and you also mentioned Toxic stalling. That might indeed be the best way of dealing with her, for the most part, especially if you run something like specially defensive Aya as a dedicated Tenma counter.
However, offensive Tenma has the option of just running Sonicboom (since Aya is a well-known Tenma counter, and since Flying is a common switch-in against her), which you
will have trouble with; smart defensive Tenma users, on the other hand, are probably well aware that the biggest counter for support/defensive Tenma is Toxic, and, knowing that, they can just run Cleric support and make you cry.
So... yeah.
Let's all start running Explosion Mimi-chan to kill Tenma.
But then Tenma teams will just start running Ghosts or defensive Darks and make you cry.
...
Man, am I glad she's banned. How is that thing NOT imbalanced?
People who said that must never have played against her without using one themselves, really.
EDIT:
You could also *probably* counter her with either an Explosion powerful enough to OHKO her or a faster Destiny Bond.
However, let's not forget that most things running a powerful Explosion are pretty easy to see coming (read: Mimi-chan), so Tenma has the option of, like I mentioned before, just switching into a Ghost or a bulky Dark and making you cry.
Let's also not forget that she can run a physical defensive spread pretty well thanks to her typing, so if you throw in a shabby Explosion/Selfdestruct, she might just tank it if she's at full HP - and even if she's not at full HP, if you throw in a slow Explosion, she can just Roost before it happens.
Plus if you throw a slow Explosion against a Calm Mind Tenma that's managed to set up, she can just OHKO you before it happens, and Explosions that are BOTH slow and strong are really, really easy to see coming (read: MIMI-CHAN); if you throw a super-fast Explosion against an Agility Tenma that's managed to set up, she can just laugh at your speed and hit you anyway, which is not good if you're not at full HP; the exact same can be said about Gale Tenmas, especially if you're running Explosion on something Flying-weak.
Then there's Destiny Bond. However, that only really counters the offensive variants, and even then, Destiny Bond is easy to see coming for the most part.
Also, let's not forget that, for Destiny Bond, you
have to be faster than Tenma. And let's not forget that Tenma can run
Thunder Wave (even on more offensive variants - who says that hybrid Tenma is not viable?), effectively making you cry.
So, kids, what have we learned today?
fuck tenma
Wise words, Agas, wise words indeed.