Needs some work.
I really don't have much to say on this that Mr Torture didn't already say rather well. Too much over use of fad slang such as "gay", not much actual use of the characters beyond their sprites, I got really sick of Shadow. Yes, I know ninjas are "so f'ing sweet" just like in the eighties when all the wrestlers became ninjas for a week or three, but Shadow wasn't a very memorable character for me, and it seems a good 2/3rds of this flash is basicly blowing smoke up a peripheral characters skirt.
Horribly bad spelling and grammatical errors really detract from the humor. IT'S hard to laugh at something when YOU'RE having a hard time reading it.
Correct a few problems with the ol' English skills, a little less trendy humor, and either actually use the characters or invevt some originals and this would be a straight 5. As is, it's only mediocre.