I don’t know if it is intentional but I think it should considered a bug. I discovered that if you feed a clone of the hero when upgrading a costume, you will have not an increased ability chance.
When growing an hero with a clone of itself you will have this percentages:
- 25% if not yet maxed
- 100% if maxed
But this is not true for costumes. I am trying to feed a Bane for my Bane costume: Bane is maxes so I expected 100% but instead it is 30%, so the chance you have with every other 3* of the same color when hero is maxed