Every characters projectile has a use in some form or another, so there will always be a reason to use it. Its pretty unanimous that most people see Kabal's gas blast as the best, and with good reason. His instant air projectiles are insane. With that being said, if we take a look at other projectiles such as Freddy's full screen game, like Mr Mileena said, it makes for nasty full screen traps. Other characters like Shang and Kenshi have pretty sweet projectile mind games too. I would Stryker definitely has the FASTEST projectile in the game, as it is pretty instant and you can cancel it, which is really cool.
Reptile (of course) is one of my favorites for projectile mind games, because he has 6 different speed of your good old fashioned, throw across the screen projectiles (except Ex Acid Spit), with 4 of these projectiles giving you pop up on hit. Those 6 are Slow FB, Fast FB, Ex Fast FB, Ex Slow FB, Acid Spit, Ex Acid Spit. You can do some pretty good zoning with those projectiles. Some have even said he himself is a projectile with bf2. Anyway, he is definitely my personal favorite for projectile mind games, as he is my all around favorite character.
Other characters like Cage and Skarlet can really mix it up with their projectiles and even do frame traps with them. Like I said, all characters projectiles have some use or another...unless you are Sheeva and just throw a random fireball.
