I agree.
This is even more dangerous with a X*+b18 base hero with a X c1.1 costume outfit.
It is very easy to confuse which X c1.1 costume outfit is attached to which base hero.
Did you just try to use a
fighter Boldtusk 4* b1.1 / monk 4* c1.1
or a
fighter Boldtusk 4*+b18 / monk 4* c1.1
to level your Rudolph?