I don't know if this should belong in Homebrew, or Questions.
I want to make a new Subdomain called Spell.
Basically, I want to be able to grant a certain wizard/sorcerer spell that represents Arcanality (ha, new word!) but won't overpower the priest. This came up while converting Ruornil in the BRCS, and I wanted to steal a domain from the Forgotten Realms CS (3.0) called Spell, but I suddenly thought that a sub-domain of magic might work better.
Ruornil's priests in 2nd edition have the spell abilities of a magician 1/2 their level, making them really different indeed.
Can a replacing power be a metamagic feat? It's hard to pick one, but I think Empower Spell might work well.