Vitamin C serum is mean't to be one of the best things for pigment. But you must get the right one & be religious am & pm. Or Azeliac acid.
The ultrasun, I believe will not fade pigment. It does block the sun, but is very thick/unctious. Use it carefully around clothing -it will stain pale stuff.
I would avoid it in tropical heat. I used it in strong heat & the cream combined with the sweat gave me a raised hive like rash which I had for at least 5 days & needed to use cortisone on.
It is not as good as she says it is, but would be good for hands (at blocking) & providing longer lasting protection with a cosmetic benefit.
Don't expect it to fade pigment. The actives simply aren't there. What it does do is provide a sort of 'cast' which disguises them, which is what we see when she does the 'hand' demo.