@Invader_Retro You're saying Yuuri isn't a good teammate but she's already proven to be a good teammate. See the thing is you don't need a bunch of super smart people, you just need one to come up with teh strategies, and then everyone else just needs to be smart enough to adapt, and execute the plan(which Yuuri is). Also your ability to form a clear image of something is not a product of intelligence, but rather creative thinking and mental flexibility, which is why typically this would be more difficult for a critical thinker to do quickly, because they think so deeply that it leaves a stronger imprint on their mind, and either way MC can just grab any random person if he wants to increase the list of abilities. Also the book itself has shown MC is -way- smarter than Ringo. She herself said that their debate was pretty much a curb stomping and she didn't stand a chance at all.
As for her ability...Ringo's ability is using 1/10th of what she copies, it's very unlikely for that to have much effect. Remember abilities have ranks, the numbers we've gotten are mostly from stronger abilities. You're also not realizing, that Ringo probably needs a person within a certain vicinity to copy their power, it's probably not permanent(otherwise she probably wouldn't have gotten caught) So for her to use a power at 10% effectiveness the person with 100% has to probably be around too...that's not very useful.
As for seeing powers. That is her one benefit, but again, that's a boon to green team, not actually to MC. This kinda information should be spread through all of Green team, because MC is probably clever enough to piece together the nature of someone's power by how they behave in a fight, it's the rest of the team that will need to be spoon fed the exact nature of their opponent's ability. I made several post about this all last chapter, but pretty much narratively, Ringo adds nothing to MC's personal group in terms of strategy that he can't get from someone else, other than knowing an enemies power. But as just mentioned, logically it's much better to -not- pair Ringo up with MC personally and instead have her as 'Intel department' for the entire green team. There is no way you can send Ringo with MC and Yuuri for a high risk mission either, because Ringo wont be able to defend herself and they would have to focus on protecting her.
This is all why I think it's stupid to put Ringo in their group. The only unique thing she adds is something tiny, but creates a combat liability.(Because they don't need her for coming up with powers for MC, just for knowing other's powers). If the MC wasn't so smart, then she would have more use, but because he's practically is a better version of her in the intel department, it's much more logical to put her with dumber people.