Since Feebas is included in Gen 3, it'll be interesting to see if they implement the Prism Scale, or a candy evolution. It'll probably wind up being Prism Scale, but i'm interested to see what you all think.
Has to be the prism scale. The process of evolution items is already in place and it makes no sense to develop a new system at this Time when there are so many other irons in the fire and there is already a mechanism in place.
Hopefully a new item, although the 400 Candy option is not impossible either