billd91
Not your screen monkey (he/him) 🇺🇦🇵🇸🏳️⚧️
While I respect a DM's right to not approve house rules suggested by someone else, this is so reasonable that I'd consider a DM to be weirdly unreasonable not to allow it.
Personally, I wouldn't go for it. I think the idea that radiant is good/necrotic is evil as opposite sides of the coin is not really true. I wouldn't necessarily be opposed to someone asking for a necrotic-themed alternative, but I wouldn't characterize it as something just any evil cleric would want/have access to because doing radiant damage with sacred flame implies some kind of draw upon the power of good.