1. While your shrimp girl looks fun, some things need toning down a little. Since the sound attack is based on a pistol shrimp's snapping, a sudden burst of sound seems more likely than a Gang Orca-like paralysing ultrasound move. If it were more like Jiro's attacks, that'd be fine.
2. Also, at this stage, smashing through concrete (at least with one blow) seems a bit much. I know you based that on a mantis shrimp's strength, but if you're going with her shell isn't tough enough to stop bullets, I say she should be able to crack concrete, only smashing it after several punches. Also doing this too much in succession would probably damage her shell, which of course would grow back, but that'd be a drawback in a fight. She could build up her strength over time.
3. As for your villain... Hmm, that Quirk would likely have more drawbacks than that, I've got to say. For one, all those staples and constant bio-rejection, wouldn't that be painful? Also, the peanut allergic reaction would set in faster than that, if it's bad enough for her to pass out after five minutes. She could get a very short boost of strength, like a minute or two, but if her throat swelled and her stomach cramped up in agony, that'd hinder her ability to fight.
4. Also have to say, not sure about the blood armour, since her Quirk is a side effect of immune reactions, not the ability to control the reactions themselves. At age 37 and as an experienced villain, it'd be unlikely for her to discover new uses of her Quirk anyway, and she already has regular armour so she wouldn't need it.
5. I don't know about the name of the Quirk either. Quirk names are usually snappy and to-the-point, whereas this one doesn't describe much except that it has to do with the lymphatic system.
6. Then to expand upon the villian. I would say causing a reaction in the middle of a battle would be not the best choice because her jumping around and fighting would only deplete her limited air that much faster. I would say doing this would be a last-ditch effort when she has no other option.
7. Also thinking about it, with best Staples which are not even remotely part of the original quirk. Your character's body is probably not designed to be at maximum strength all the time especially with the Staples getting infected or can gangrene. I just don't see how someone going to be at max strength all the time and not burn out because it only comes out when there's a foreign antigen in her body. I would recommend that she has enhanced strength kind of like Captain America levels normally. Because there's always white blood cells in the body. When she introduces an antigen to herself she can get even stronger. And again the allergic reaction being a last-ditch effort
First of all, thanks to the both you for your feedback. I have reviewed your points and have numbered them, and I will address them accordingly.
1. The last time I tried to use this character in an RP, someone pointed out that a pistol shrimp's ability only works underwater, so I offered Gang Orca as a counterexample since technically, his ability should only work underwater as well. But you're absolutely right, I never intended for the Pistol Shot Attack to be paralytic, it was always intended as a 'sonic bullet'; a ranged concussive blast like a small cannon or shotgun, meant for damage and not for crowd-control. It was always that way in my head, but I forgot to convey it thus.
2. I can for sure tone down the strength. I do want XiaoPao to learn the Pistol Shot Attack and Mantis Punch through her education, so you're right, being able to punch through concrete right now doesn't make any sense. I was thinking that she had incredible grip strength, but the utility of that would be limited, since whatever she's trying to crush would have to be able to fit in the relatively small gap between her pincers.
3. So I'll admit I nerded out a little when coming up with Shifumi's quirk. Having majored in bioengineering, I learned about the drawbacks and limitations of artificial implants. While not antigens in their own right, certain plastics and metals will, over time, become irritants that the body will react to, creating a passive inflammation which taxes the immune system. Since Shifumi's concept is heavily inspired by another character with magical, strength-boosting staples in their body, I thought a quirk that turned passive inflammation into strength would be an interesting way to turn this character into a bitter, MHA villain. I was thinking that while the process of embedding the staples was initially painful, her body has gotten used to it, like how people in the past who got shot and survived sometimes just went through life with a bullet inside them because they didn't know how to get the bullet out at the time. I'm also considering that the toxins in her system have crippled her kidneys and liver, meaning a hit to those organs would knock her out. But this isn't much of a weakness since she wears armor, so it would be hard to get a hit to her lower back or gut. Ingesting alcohol would probably kill her though, making sake-less yakuza rituals super awkward. But yeah, I can for sure limit the peanut allergy technique to just one minute, and something she only uses as a last resort.
4. I'm totally fine completely removing the blood armor idea.
5. The name of the quirk was a reference to the competitive taunt, "Do you even lift, bruh?", highlighting Shifumi's Chad-like strength. I thought it was a clever pun, since most if not all of the MHA character names are puns or references (both my characters have punny, referential names). But you're right, it is a little long as far as quirk names go. Maybe I'll just go with 'Super Serum', since that's literally what it is, serum (blood plasma) that gives super strength.
6. I addressed this in 3
7. I partially talk about this in 3. But I can definitely tone down her passive strength. I can also say that skin has grown over the staples so that they are not open wounds so there is not a constant threat of infection or gangrene. I think the passive inflammation giving her Captain America levels of strength is fair. As for applying an antigen to boost her strength, I'm trying to think of what's good. Obviously, the peanut allergy is fairly lethal and should only be used rarely, if ever. But an actual bacterial or viral infection is something that takes time, so stabbing herself with a syringe of influenza virus is not something she can use in battle in a dependable way. So I thought of something that might strike a good middle ground. Shifumi collects extract of poison ivy. Her armor hides canisters of the powder. If she wants to get serious, she presses a button, an itchy mist is released from her armor, coating her skin. It sucks to experience, but its a more-or-less immediate, and more importantly, non-lethal immune reaction taht her quirk can take advantage of.
So please let me know what you think of these revised ideas. If they are ok'd, I will apply the revisions to my CS's for a second review.