Dervish might work, but she was a one trick pony with forms IMO.
Modern warrior kind of took the place of Paragon with Standards and Shouts.
I don't know: what Niche is missing?
well, jsut because the mechanics are same as engineer, doesn't mean they can't change the ritualist up a bit so atleast they could transfer the same feel the ritualist gave. Nothing beats a ritualist imo ^^ favourite class ever