How to be OP in Tokyo Mew Mew.
Local to Planetary Scale Threat:
Most of the verse's fighters are here, and statwise are in the MHS Town to City Level Range.
This was a lot trickier to find counters then you'd expect, not because the verse is particularly but just because there is a general lack of weaknesses in the verse.
Max Range is city level which for town to city level characters is on the better side of normal I'd say. Stamina is pretty good. Intelligence builds probably wouldn't do very well since the verse already had advanced tech and one supergenius. Stealth probably wouldn't do very well since Ichigo has catlike senses and Zakuro has wolflike senses, as well as the natural abilities of the Kirema animals and the advanced sensor technology. Verse has a natural psychic, Royal Highness who showed city level mental attacks, so psychic builds most of the time not a great pick. Verse is just really consistent for it's tier.
Avoiding that mental attack is probably one of the biggest challenges the verse presents. Beyond that the Mew Mews themselves possess "mew power" which reverts things to their natural state on a molecular scale. So a character whose abilities are natural. Yet at the same time any animal is probably a bad pick as they could be converted to kirema and be taken control off.
So that's interesting, what we are looking for is a character with natural abilities but who is still sentient. So outside of characters who developed techniques, we're looking then for characters like fantasy humanoids, mutants or sentient aliens. Or perhaps just characters who developed their techniques...
That gets me thinking. In Most TMM fight scenes the Mew Mews avoid getting into close range with the kirema animals, and those are just wild beasts. Close Range combat seems to be a weakness suggesting builds with high strength and melee skill might be the way to go. Yes, a good viable tactic against most of the verse would be to get in close and pressure them with powerful melee strikes, especially since most of the verse needs to make specific movements to use their abilities. Even Kish's dupliciation while still strong might struggle with this since one of the biggest potential counters to duplication is being so skilled that fighting 1 opponent or many makes no difference. A really skilled melee martial artist build that can do damage to them would be a really good pick, for instance
Ryoga Hibiki from Ranma 1/2. I would have put Ranma himself but Ranma's fear of cats is not good for fighting Mew Ichigo. Ryoga's embarrassment at the sight of women's breasts is unlikely to apply here as the Mew Mew are mostly rather young and are not very developed very much.
In terms of combat, Ryoga's power would be comparable to the Mew Mews, and he might lack a bit in range compared to them but in close quarters he's so much more skilled and agile as well as just physically strong, it would be ridiculous. His sixth sense would help fight multiple opponents if it came down to it and he could quickly get himself out of being encased in pudding by Mew Pudding if he uses Bakusai Tenketsu.
I don't think this is the perfect counter since he could still be affected by the artificial Kirema diseases and Kirema Butterfly's toxic air would likely affect him, that said against any of the fighters in a direct one on one fight their only chance would be to stay at range.
What would be ideal would be a character resistant to diseases, who can match the verse in power, is highly skilled and strong, and also has ranged attacks...like....
Piccolo Daimao from Dragon Ball would be an excellent counter to anyone in the TMM-verse outside Deep Blue. Not only is he a Namekian meaning he would resist mew power since it's his natural state, but his raw power is comparable to the top tiers yet he can also form defensive ki barriers which makes him and has natural very difficult to overcome regen meaning it would be extremely difficult to put him down. Meanwhile he can nuke them with energy at their limit from out of their range or can melee them with strength and skill op for the verse. Also considering how old Kami is (hundreds of years) it's clear Earth pathogens like Kirema viruses would be unable to affect or at least affect very quickly Namekians like Piccolo Daimao
Now granted his speed is a touch low for the verse, That said outside a combined attack from like everyone in the verse, I can't imagine them overpowering him via speed.
If you want a non-skill build then it becomes tricky because again the verse lacks general weaknesses though there is another alien character I think would be extremely effective in the verse.
Carnage would be on the weaker side of the verse's power but his abilities would make him almost impossible to stop. First off his symbiote form is his natural state so mew power isn't hurting him. The verse lacks heat or sonic based attacks but even ignoring that Carnage has atomic scale regeneration. TMM completely stops at the molecular scale meaning no one would be able to purify or infect Carnage, even ignoring the fact that Carnage is immune to Earth diseases.
And the sheer HAVOC he could wreak. Carnage can infect the verse, similar to Kirema, that said his infectation would be incurable since it's atomic rather then molecular, and he could quickly duplicate overtime without any ability to stop him. Carnage could basically recreate the events of Maximum Carnage in the TMM-verse and be nigh-unstoppable.
It helps that he's a very direct and desires to kill then the verse and is a way better melee fighter then most of the verse. I initially thought to use Taskmaster instead but Taskmaster has the issue of no very long range attacks. Carnage doesn't have that problem as his infection tendrils can stretch across an entire city.
Galactic Scale Threat:
There's only one character on this level, namely Deep Blue. Deep Blue's an interesting sort of method of test character. He has an ability that can bring a world to total oblivion, can tank that own attack, can trap things in light orbs which can tank his own attacks, can blitz MHS characters...
Deep Blue is really hard to bring down sticking to only his own level of power and speed outside of abusing some cheese strategy like using an intangible. Even then Deep Blue supposedly could kill an alternate consciousness so intangibility MIGHT not be a good counter strat.
You also can't really rely on turning his powers against him since he can tank his own attacks and teleport meaning you can't trap him in a light orb.
In terms of weaknesses, Deep Blue's actual planet busting attack takes a few seconds to charge. His normal half-awake strikes can release town levels of energy and just powering up his big attack can destroy a city, but any character nearly as strong as him can just tank that.
Also Masaya's self wants to destroy Deep Blue from within him to protect the Earth.
So basically someway to bring Masaya out, and being able to exploit a slight delay are the best strategies. The big problem is somehow being able to kill a character that can blitz MHS characters and can tank planet busting attacks.
Even assuming you don't want to cheese it with some kind of defensive hax based strategy, a cerebal/hax based character might work, for instance
Lucifer from Dante's Inferno. Multi-Continent Level is probably not gonna be able to kill Deep Blue via raw physical power but the sheer mind games Lucifer would play with Deep Blue...
Assuming this is Lucifer's true self rather then Lucifer's projected shadow self, Lucifer could only really die if Deep Blue focused his full planet busting attack on Lucifer. Sure Deep Blue could capture Lucifer in a light orb but that's really just gonna be a forcefield for Lucifer while he uses his non spatially transmitted abilities. He can see through space and time and would know Deep Blue's weakness and could casually create illusions of Ichigo suffering to bring out the Masaya Personality. Lucifer is supposed to be a master manipulator so this would be easy.
Beyond that Lucifer can teleport and can take the form of smoke and fire (logia intangibility), making it even harder for Deep Blue to kill him.
Beyond that Lucifer has soul manipulation and was also able to cause the scythe of Death to disintegrate suggesting he could ignore Deep Blue's physical durability.
Deep Blue might be faster but Lucifer could easily avoid or exploit all of Deep Blue's abilities and play him with his manipulation, mental and soul abilities, and ability to see across spacetime.
For another unconventional strategy you could use Homura from Puella Magi Madoka Magicka (in her base state obviously). Not only is she comparably fast, but she can freeze time at will as well as survive Deep Blue beginning to charge it meaning so long as Deep Blue doesn't leave Earth orbit, Homura can simply freeze time when he starts to charge it.
But what does she do then? Well the Wraith Arc gave Homura memory manipulation abilities meaning she could erase Deep Blue's memories which would revert him to Masaya and that would be gg, especially if she decides to end him there.
But what if he does quickly leave orbit? Homura can go back in time and stop him. Not a hard one :P
There's one more character I wanted to propose that would so perfect ability wise and thematically, but the character is just slightly too fast at Relativistic Speeds. That said if you are looking for speed equal counters or it's ruled ok because of some metric like Deep Bliue can blitz MHS characters so the speed gap isn't very big, then I have the perfect Deep Blue counter.
Get ready for this...
Captain Planet.
First off, Captain Planet is Multi-Continent in dc which considering he can concentrate all his powers into a single rainbow beam could actually be able to kill Deep Blue if he hits him say in the eye and he is particularly precise. More notable, Captain Planet could literally toss Deep Blue into the sun, something that would probably kill Deep Blue due to radiation and moreover would definitely take him a while to get back from. He also seems to have some form of transmutation as he was able to convert mud into a pair of sunglasses.
But this is just scratching the possibilities. Captain Planet also has logia intangibility (light) meaning that he could avoid Deep Blue's attacks as mentioned earlier. He has a form of light based teleportation meaning that if he got trapped in a Light Orb he could simply teleport out as well as become light and simply go through the light orb as photons.
But this brings us to the big thing. Captain Planet has the power of heart which not only would be able to sense the presence of both Masaya, who is noble, and Deep Blue who is evil, it would be able to change the emotional state of Deep Blue likely reverting him to Masaya as it can revert things to a non-aggressive state. Even if not he could likely still get through to Masaya via Heart-Based Telepathy, since the thing Masaya cares about deeply is the Earth and nature. He could also use the power of Heart as seen in the comics to knock Deep Blue unconscious by forcing him to look into the darkness in his own heart, which would give Masaya another chance to gain control and at the very least give Captain Planet all the time he needs.
You might be thinking "hang on a minute wouldn't Captain Planet be debilitated by Deep Blue's hatred" but Deep Blue actually isn't full of hatred. He is noted as being apathetic towards all life and wanting to destroy it merely because he views it as inferior. Deep Blue's lack of real hatred means he would not be able to defeat Captain Planet with it.
And that's how to be OP in Tokyo Mew Mew