They can be created anyway in a mid range radius from you(10m).They're not,they have pretty much the same strength as if you threw the senbons,although they would move slightly faster due to being chakra propelled.
This will come real handy in battles.
(Fuuton: Chishi) - Wind Release: Fatality
Type: Offensive
Rank: A
Range: Short - Mid
Chakra cost: 30
Damage points: 60
Description: The user will infuse two weapons with wind chakra by simply touching them, the user will then throw them at opposite sides of the opponent completely missing them, at the moment the weapons pass by the opponent the user will perform an handseal connecting thefuuton chakra from both weapons forming a dense green coloured line of fuuton chakra which has the same cutting power as the Wind Blade technique between both weapons cutting the opponent. The maximum distance that can be between these two weapons for this technique to work is mid-range (fifteen meters).
~Can only be taught by Mako.
~Can be used thrice in a battle.
This is quite simple although you don't necessarily have to throw it, you could infuse two blades, use our Bartholomew jutsu to teleport one of the blades behind the opponent and bang!, Sneak attack