Sorry one more I believe its Sylars sword and he loses it to Hiro some how maybe next week he drops it or something when battling Peter and Clair?
Hmmmm, very interesting thought... I like it! Lol... but then again, if Sylar ever found Hiro and saw him using his sword, he'd probably be a little angry and use his TK to chop Hiro into sushi, lol. Though, we noticed that the sword protrudes from Hiro's back quite a bit, so it would be hard to not see it sticking out from Sylar's back, despite the fact that he is wearing a trench coat. But going along these same lines, Two ideas of how Hiro obtains his sword:
1) The one that Munipilater just mentioned, and that would be it originally being Sylars and Hiro obtains it. I highly doubt that Hiro will be able to take on Sylar himself anytime soon, so perhaps Peter is in the midst of fighting Sylar, he is gravely injured on his face by the sword, but before Sylar is able to kill him, Hiro stops time, gets Peter out of the way, they injure Sylar and take his sword away in the process. Maybe Peter gives Hiro the sword as a token of appreciation that Hiro saved his life. (Hey sounds crazy, but look at who you're talking too... I'm the master of absolutely ridiculous theories, haha).
2) My 2nd idea is that either right now, or sometime in the near future, Hiro over shoots his travelling to the past and ends up in Feudal Japan where he learns to train as a samurai. My line of thought is that somebody sees him using his power, and they praise him as a result, as a magical man with powers, or Godlike figure. Thus, they are willing to train him in the art of the samurai and give him a sword. I highly doubt that a normal person would be accepted so willingly and be offered some training... but somebody with powers... hmm...
In terms of the severing of the heads, I originally suggested that because of the preciseness of the cut, and because the brain might need to be in tact, that Sylar may possess some kind of Cyclops or Psylocke energy emitting ability that can make such a precise incision. After tonight's incision, and the coincidence that the girl had also just finshed opening the top of a can, I believe that Sylar may just use whatever he has in front of him to cut their heads open. I think that he has developed his power so much so that he can make things move faster than the eye can see. Maybe this is how he gets into the back of the kitchen, he has the ability to even make HIMSELF move telekinetically, faster than the eye can see, which in itself seems like super-speed to us (like Quicksilver or something like that). Just some more of my ridiculous Popkorny food for thought
Not to gross anyone out, but I have cut a skull in a somewhat similar fashion and removed an intact brain. It was much slower and it was a fetal pig's brain. There is fluid between the brain and the skull. Think about the lack of damage to the contents of the can when you remove the lid.
Second, a Katana can cut through bone and actually can cut through the whole human body. The common stroke used was a slicing stroke using two hands (usually downward) with a slight twist and pull at contact to get past the first layer. Once past the first layer, the stroke is continued throughout the body. The reason the Katana can do this is similar to the reason the scalpel can do it, they both have one sharp edge and one blunt side, with the blunt side adding hardness and stability to the whole tool, while the sharp edge makes the initial push. The smoothness of the whole tool allows it to pass through easily without hitching (although I would use a scalpel more as a brush than as a cleaver).
What the Katana cannot do is be used as a blocking/parrying weapon or slash instead of slice.
I think we can assume future Hiro isn't Sylar because unless he gets wicked twisted, he would never kill Charlie.
As for what does the cutting, its gotta be something thin, since we didn't see anything below the cut when Charlie's head was cut. It may not be any one item either. He could just grab something around him and use it on his victim. There was a gun when Issac was killed, so maybe he doesn't have one thing. We seem to be ignoring the fact that it could be more then one thing, nothing consistent. That's my new idea since he didn't seem to be carrying anything big on himself at the diner.
HAWKDRAGON, your signature got me thinking about something. When had she seen him concentrating before he dutifully displayed it for her after her compliment?
1. Since Hiro has to go back in time to fix her death and presumably has to "wobble" at least once (to get back or to protect her), she remembers that even though she shouldn't since this is a different her.
2. She crossed paths with Hiro before but doesn't quite remember, but remembers this trait. It is sort of similar to remembering trivia but not remembering where you learned it.
If this is true, the payoff of course would be if we see this happen in the next episode.
1. Since Hiro has to go back in time to fix her death and presumably has to "wobble" at least once (to get back or to protect her), she remembers that even though she shouldn't since this is a different her.
2. She crossed paths with Hiro before but doesn't quite remember, but remembers this trait. It is sort of similar to remembering trivia but not remembering where you learned it.
If this is true, the payoff of course would be if we see this happen in the next episode.
A third possibility is that due to the time compression inherent to linear video storytelling, she has had time to observe Hiro squinting and huffing his cheeks during a time that is not expressly included in the story. Ando and Hiro were in the diner for maybe 4 minutes maximum in the tv show. But in the story it is reasonable to expect they were there for at least 45 minutes. That would be enough time for her to develop the crush and notice his cheeks.