Well, that's pretty much how kevlar does behave. It's more or less tear resistant, and a kevlar vest will stop conventional fire arms and knives, but a close range shot would either get through, or knock you flat on your ass and knock you out. Now, the chest area would obviously be much less flexible and lightweight than the rest of the suit, but kevlar vests have gotten alot more compact and flexible and recent years, so it wouldn't be overly constricting if properly made. The main problem with a suit like this is that it would be ****ing hot. A guy would probably over heat very quickly if they were fighting while wearing this thing. So, I'd suggest that whoever's doing this should wear rubber tubes full of ice water under the shirt in the warmer months to keep themselves from over heating. And have the mask be easy to take of is you feel especially warm at any point.
