You have to get a score of 175 playing upside down in Zen mode.
Get 1 million
To get the lightning bolt blade, you have to get 10000 starfruit.Since its a elite blade you have to use starfruit to unlock it.
get a score of 204 hitting no bombs, slicing all of the bannas and getting a 5 fruite combo
Get at least 175 in Zen up side down
It's the lite version, in order to unlock anything you need to get the full version.
you get it in the beginning
to unlock the pixel love blade in fruit ninja is you have to get 50 combos i classic mode and if you go to dojo in the main menu the mango then go to senseis swag the pineapple look for the pixel love blade and it will tell you how to get it and how many more combos to go
Buy it
there is no "best blade". they all do the same thing {cut fruit}
you unlock it in a cheat
Buy it
The shadow blade is at full power when you reach lvl 70. It's DPS is 39 and the speed is faster