Don't know why this is a subject here. But Irene is a Classic character from the NES era, she is also the only character "close" to ryu in that sense, and while she and rachel are visually similar (busty blonde), they're kinda different characters all together. I honestly think it would be cool to have a woman soldier type of character in the series, they could give her an interesting moveset. And i'm all for ninja gaiden references and nods in general.
That is it.
Now back to topic, i think most of the costume selection this year was good for the halloween designs, last year it wasn't great, this year, a bunch of really solid designs.