You'd probably have to partially nerf/merge some Samurai skills to make it properly work, but I think Kaiten could be brought back, IF it reduced variance by making the next attack a guaranteed Crit. I get why SE removed it (it feels bad when your big attacks don't crit, and it was a recognised problem with Samurai), but the animation and fantasy were arguably iconic to the job, and removing Kaiten was the wrong choice to make.
