Depends on how you want to run the campaign, is it something extremely unique (Stolen Soul/Harrowed) or something that is rare or uncommon (Vampire/Undead). Hmmm, Casts No Reflection would fall under this too, wouldn't it?
Change Environment with a PER modifier, self only, no range, constant, reduced end, probably a few more limitations to add to it as well. I'd have to pour over the limitations list to see what works well. As a power it would need to be resistant to nullification effects of those sorts which would lend itself to Distinctive Features but it all depends on what is prevalent in your milieu.