Can Toph Blood Bend?
Listen, before you get your panties in a twist let me just ask you this question, are there really any limits to bending? Our world shares so many qualities to the main four elements that technically there really might not be an limitation to anyone with the ability to bend. With that being said, of course there are specialized bending in the world of Avatar the Last Airbender that have already been discovered such as Blood Bending, Metal Bending, etc. With a little bit of ingenuity, Katara was able to bend her own sweat to use as a sort of blade to break open the wooden jail cell her and Toph were thrown into after being captured pulling scams in Season 3. Amazing isn't it? Katara was taught to blood bend by that crazy old hag Hama and even how to rip water from flowers. With such little things being taken into consideration, it isn't a stretch to say the greatest earth bender of all time, nicknamed the runaway and the blind bandit could have the ability to blood bend, now is it?
Now to put it simply, Toph is lowkey OP as hell. Toph is my favorite character in the entire series and actually inspired me to pick up martial arts. I am still to this day looking for a Southern Praying Mantis Style Dojo but thats a story for another time. To be honest, I binge watch this series once a month without fail. The story and the development of the characters was so mature for the age rating of this show. To put it plainly I obsess and with that obsession I've paid close attention to each characters abilities, personalities, and theoretically what they could do with their bending with a little extra focus and dedication. Toph has already mastered the art of earth bending, founded the style of metal bending, perfected her sand bending after years of practice, and can sense the earth in anything outside of platinum, theoretically. Again, this probably could still be done through her seismic sense but lets just give her this one L. With Toph's seismic sense she can easily detect the earth particles in literally anything. So who's to say if there was enough iron in an individual's blood stream that she wouldn't be able to use that iron to bend them physically to her will?
This thought has been explored in characters outside of the world of Avatar as well. For example, Magneto, a mutant from the universe of X-Men. He is a well known adversary of Professor X and has the ability to bend metal. Hey, maybe Toph is his great great great great great great great great grandmother. That would be one heck of a twist wouldn't it even if it was just for shits and giggles.
Anyways though, Magneto once graced the pages of a well known story line where he literally ripped the adamantium from Logan code name Wolverine's body. Adamanatium in the Marvel Universe is the purest and strongest metal known to man only second to Vibranium. If Magneto has the ability to literally rip metal from bone through the flesh of an individual whose to say Toph couldn't do the same? The process would probably require a lot of focus on her part as well as vigorous training that resembles Hama's during her stay in a fire nation prison, but it could be done.
It is known that the human body holds several minerals within itself. Minerals such as Copper, Zinc, and Iron just to name a few can be found throughout our systems, all of which were probably used to develop metal during Toph's lifespan in the world of Avatar including both The Last Airbender and the Legend of Korra. But is there enough of these metals in the human body for a metal bender, such as Toph, to have the ability to utilize them?
Well according to the Iron Disorders Institute, the average male have four grams of Iron in their body while the average female has about three point five grams while children of both sexes have about three grams or less. These grams are distributed through the body in hemoglobin, tissues, muscles, plasma, and guess what, blood proteins. Now to be fair, that isn't exactly a lot to work with, but Toph is no stranger to utilizing trace elements of rock and metal to bend to her will.
When first faced with the sand benders, Toph exclaimed that she couldn't control the material well and her seismic sense was too fuzzy to make out objects around her. After this defeat as the show progressed into the third season , Toph spoke about the fact that she had been practicing her sand bending. She was able to replicate a sand version of the earth kingdom complete with the earth king and Boscoe. It seems with added practice that she became proficient so is it a far stretch to say that maybe she was even able to master this ability?
According to Live Science, the most common component of sand is silicon dioxide in the form of quartz, feldspar, and mica. With such a small availability of her usual bending materials, it makes sense she would originally struggle. With her learning to perfect this particular type of bending it is quite plausible that she can blood bend and here's how. The human body carries trace amounts of metals that get carried through our bloodstreams.
The number of these metals can vary greatly based on genetics, diet, etc. Unlike Katara and a full moon, Toph would not have a specific time where her abilities could be heighten, so extreme focus on Toph's part and use of her seismic sense will be necessary. In the way that sand holds very small bits of weathered rocks, the body holds small bits of metal. With the use of her seismic sense Toph is able to tell if someone's lying, about to attack, about to die, and so much more. All of these small details make it possible for this same sense to be used in an attempt to find minute traces of metal in the blood stream.
Now in theory, this works, but in practice who would actually have the time to physically manipulate the metals in blood. The metal will not boast the same amount of water in the stream that makes blood bending relatively easy for water benders. There is enough flowing. Toph Beifong could indeed blood bend, but it would not be as graceful and would probably be easier if her enemy is subdued in a similar way that Aang subdues Firelord Ozai to give himself the time and focus to remove his bending.
With the same conditions, Toph's innate ability to sense and bend both metal and earth, she could theoretically at the very least, rip the metal piece by piece in the same fashion that she does for Korra, but of course with more ferocity. She has already proved herself capable of sensing trace amounts of metal, it would just take her in her prime to weaponize it instead of using the ability for healing like she does for the newest avatar in the Legend of Korra. To clarify, Korra was able to remove the metal from her system but Toph was the one who knew it was in her body. If Korra can do it and its not even her main element, Toph could literally do this in her sleep.
So yes, Toph Beifong indeed has the ability to blood bend, in a sense. She has the ability to sense and mobilize the metal in the human body which not only makes her the greatest earth bender of all time, but a real force to be reckoned with.