Heck with ninjas. Let's mix things up and be samurai.
Yeah, all the cool pictures have lots of blood. x.o
As far as time goes... What did you have in mind? I mean, time itself is interesting, but what can we do with it? I can't think of anything at the moment. ^^; Aside from time manipulation. But that seems a tad overpowered and specific for a team. I do agree with Scott, though. I think we need some basic idea and roll from there.
And in all seriousness, I think modern day samurai would be awesome, but I have no idea how we could work that. xD