If you sort the hero roster by power, it will adhere to the current power rating of the hero (regardless of rarity), these ratings and placement in your roster take into account of Emblems you place on the heroes.
However, I have noticed perhaps a minor, or insignificant issue with the introduction of costumes. That is the sorting / resorting of the roster can sometimes have a costumed hero go up and down the roster.
Bane’s costume was one I acquired during the event. I don’t emblem my 3* heroes. An unemblemed Bane maxes out at 440 power rating. I started working on the costume off of my maxed 3^50 Bane, since it is unlikely one works on original Bane any more, you kind of leave him on the costumed version and keep feeding feeders to him. A 1^1 costumed Bane would have much lower power rating, which should be placing him towards the bottom of your roster.
But instead, his place on the roster every time I go in seemed to be placed around where he was at 440, next to maxed Dawa, who has identical power rating. But things changed and he started moving up the roster chart despite still not full, and have a 300 something. Then it dawned on me that it must because with each costume ascension, there are going to be bonus stats applied to the original, which is likely what the roster is still sorted by, and switching back to the original Bane confirmed this, he is no longer at 440, but higher 454 now (3rd tier), taking him past (or to the left of) Melia/Muggy, both unemblemed at 450.
However, if I switch back to costumed Bane, with the 377 rating and hit sort by power, his place is now dropped down to the bottom of the roster. If I jump out of the hero roster screen and go back in, he is again, sorted by his altered original stat, being placed to the left of Melia / Muggy.
This happens also when costume is toggled during a session, resorted that places him/her elsewhere. Only to be sorted back again to the original spot before the first session’s sorting, when the hero screen is backed out and returned again.
Again, not sure if this is big enough issue, but I could see it “possibly” creating some inconvenience/annoyance once multiple costumes are acquired, and frequent users of the sort may have to look up and down their roster to see the hero they are working on.